Dr. hab. Bivas Rana, Prof. UAM

Dr. hab. Bivas Rana, Prof. UAM

Department of Physics of Nanostructures

Tel: +48 61 829 5191
Loc: wing G, first floor, room 184
Email: bivran@amu.edu.pl
URL: http://bivasrana.weebly.com/

Scientific degrees

PhD in physics – 2014
Habitation in physics – 2023

Research interests

Keywords: spintronics, magnonics, voltage-controlled magnetic anisotropy, magnetic damping, magnetic skyrmions

Currently, I am working on the investigation and manipulation of various types of physical phenomena such as perpendicular magnetic anisotropy, damping, Dzyaloshinskii-Moriya interaction originated at the interfaces of magnetic heterostructures. The purpose is to utilize these interfacial phenomena for the control of spin wave properties, properties of magnetic skyrmions and coupling between magnons with other quasiparticles such as phonons with an ultimate goal to develop energy efficient miniaturized microwave devices for future technology.

Scientific achievements

Best Oral Presentation in “Bosefest 2012”, S. N. Bose National Centre for Basic Sciences, India, February 2012,
Best Poster Presentation in “9th International Conference on Physics and Application of Spin-Related Phenomena in Solids”, Kobe, Japan, August 2016,
The “First Degree Scientific Awards of the Rector” of the Adam Mickiewicz University, Poland for scientific achievements in 2022,
Selected as “Emerging Leaders 2022” by Journal of Physics: Condensed Matter >>>.

Editorial Board Membership

Editorial Board member (EBM) of Communications Physics since October 2023 >>>,
Serving as a guest editor for the focused issue “Role of various coupling phenomena on recent progress in magnonics and magnonic metamaterials” in Journal of Physics: Condensed Matter >>>.

Projects

Bivas Rana

Magnon-phonon coupling in Magnetic 2D heterostructures in presence and absence of skyrmion lattice

2021 - 2024, (NCN SONATA 16, No. 2020/39/D/ST3/02378, budget: 1 617 953 PLN).

Links | BibTeX

Publications

2024
17.	Bivas Rana, YoshiChika Otani Development of Magnonics with Voltage-Controlled Magnetic Anisotropy Bandyopadhyay, Supriyo, Barman, Anjan (Ed.): Nanomagnets as Dynamical Systems: Physics and Applications, pp. 71–96, Springer Nature Switzerland, Cham, 2024, ISBN: 978-3-031-73191-4. Abstract \| Links \| BibTeX @inbook{Rana2024, title = {Development of Magnonics with Voltage-Controlled Magnetic Anisotropy}, author = {Bivas Rana and YoshiChika Otani}, editor = {Supriyo Bandyopadhyay and Anjan Barman}, url = {https://doi.org/10.1007/978-3-031-73191-4_3}, doi = {10.1007/978-3-031-73191-4_3}, isbn = {978-3-031-73191-4}, year = {2024}, date = {2024-11-10}, booktitle = {Nanomagnets as Dynamical Systems: Physics and Applications}, pages = {71--96}, publisher = {Springer Nature Switzerland}, address = {Cham}, abstract = {This chapter discusses the origin and essential features of interfacial magnetic anisotropies and voltage-controlled magnetic anisotropy (VCMAVoltage control of magnetic anisotropy (VCMA)) in ultrathin ferromagnetFerromagnet/oxide heterostructures. Various other electric field-induced methods for controlling magnetic properties and the advantages of VCMAVoltage control of magnetic anisotropy (VCMA) over them are thoroughly discussed. The recent progress of magnonics with VCMAVoltage control of magnetic anisotropy (VCMA) is described in detail. In particular, we discuss the linear and parametric excitation of ferromagnetic and spin waveSpin wave (SW) resonance; the essential properties of spin wavesSpin wave (SW) guided through reconfigurable nanochannels; the manipulation of spin waveSpin wave (SW) frequency, phase, wavevector, magnonic band structures, and damping parameters in detail. A brief discussion follows on the excitation and manipulation of spin wavesSpin wave (SW) by various other direct and indirect electric field-induced methods. The chapter concludes by briefly describing some open challenges in this field.}, keywords = {}, pubstate = {published}, tppubtype = {inbook} } Close This chapter discusses the origin and essential features of interfacial magnetic anisotropies and voltage-controlled magnetic anisotropy (VCMAVoltage control of magnetic anisotropy (VCMA)) in ultrathin ferromagnetFerromagnet/oxide heterostructures. Various other electric field-induced methods for controlling magnetic properties and the advantages of VCMAVoltage control of magnetic anisotropy (VCMA) over them are thoroughly discussed. The recent progress of magnonics with VCMAVoltage control of magnetic anisotropy (VCMA) is described in detail. In particular, we discuss the linear and parametric excitation of ferromagnetic and spin waveSpin wave (SW) resonance; the essential properties of spin wavesSpin wave (SW) guided through reconfigurable nanochannels; the manipulation of spin waveSpin wave (SW) frequency, phase, wavevector, magnonic band structures, and damping parameters in detail. A brief discussion follows on the excitation and manipulation of spin wavesSpin wave (SW) by various other direct and indirect electric field-induced methods. The chapter concludes by briefly describing some open challenges in this field. Close https://doi.org/10.1007/978-3-031-73191-4_3 doi:10.1007/978-3-031-73191-4_3 Close
16.	Bivas Rana Role of voltage-controlled magnetic anisotropy in the recent development of magnonics and spintronics Journal of Applied Physics, 136 (15), pp. 150701, 2024, ISSN: 0021-8979. Abstract \| Links \| BibTeX @article{10.1063/5.0233693, title = {Role of voltage-controlled magnetic anisotropy in the recent development of magnonics and spintronics}, author = {Bivas Rana}, url = {https://doi.org/10.1063/5.0233693}, doi = {10.1063/5.0233693}, issn = {0021-8979}, year = {2024}, date = {2024-10-16}, journal = {Journal of Applied Physics}, volume = {136}, number = {15}, pages = {150701}, abstract = {With significant recent progress in the thin film deposition and nanofabrication technology, a number of physical phenomena occur at the interfaces of magnetic thin films, and their heterostructures have been discovered. Consequently, the electric field-induced modulation of those interfacial properties mediated through spin–orbit coupling promises to develop magnetic material based smarter, faster, miniaturized, energy efficient spintronic devices. Among them, the electric field-induced modification of interfacial magnetic anisotropy, popularly termed as voltage-controlled magnetic anisotropy (VCMA), has attracted special attention because of its salient features. This article is devoted to reviewing the recent development of magnonics, which deals with collective precessional motion of ordered magnetic spins, i.e., spin waves (SWs), and skyrmions with chiral spin textures, with VCMA, including the perspectives of this research field. Starting with a broad introduction, the key features of VCMA and its advantages over other electric field-induced methods are highlighted. These are followed by describing the state-of-the-art of VCMA, and various other direct and indirect electric field-induced methods for magnetization reversal; controlling skyrmion dynamics; excitation, manipulation, and channeling of SWs; and tailoring magnonic bands. The critical challenges, their possible solutions, and future perspectives of this field are thoroughly discussed throughout the article.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close With significant recent progress in the thin film deposition and nanofabrication technology, a number of physical phenomena occur at the interfaces of magnetic thin films, and their heterostructures have been discovered. Consequently, the electric field-induced modulation of those interfacial properties mediated through spin–orbit coupling promises to develop magnetic material based smarter, faster, miniaturized, energy efficient spintronic devices. Among them, the electric field-induced modification of interfacial magnetic anisotropy, popularly termed as voltage-controlled magnetic anisotropy (VCMA), has attracted special attention because of its salient features. This article is devoted to reviewing the recent development of magnonics, which deals with collective precessional motion of ordered magnetic spins, i.e., spin waves (SWs), and skyrmions with chiral spin textures, with VCMA, including the perspectives of this research field. Starting with a broad introduction, the key features of VCMA and its advantages over other electric field-induced methods are highlighted. These are followed by describing the state-of-the-art of VCMA, and various other direct and indirect electric field-induced methods for magnetization reversal; controlling skyrmion dynamics; excitation, manipulation, and channeling of SWs; and tailoring magnonic bands. The critical challenges, their possible solutions, and future perspectives of this field are thoroughly discussed throughout the article. Close https://doi.org/10.1063/5.0233693 doi:10.1063/5.0233693 Close
15.	D Panda, K K Behera, S Madhur, Bivas Rana, A Gloskovskii, Y Otani, A Barman, I Sarkar Role of the nonmagnetic underlayer in controlling the electronic structure of ferromagnet/nonmagnetic-metal heterostructures Phys. Rev. B, 110 , pp. 094424, 2024. Links \| BibTeX @article{PhysRevB.110.094424, title = {Role of the nonmagnetic underlayer in controlling the electronic structure of ferromagnet/nonmagnetic-metal heterostructures}, author = {D Panda and K K Behera and S Madhur and Bivas Rana and A Gloskovskii and Y Otani and A Barman and I Sarkar}, url = {https://link.aps.org/doi/10.1103/PhysRevB.110.094424}, doi = {10.1103/PhysRevB.110.094424}, year = {2024}, date = {2024-09-18}, journal = {Phys. Rev. B}, volume = {110}, pages = {094424}, publisher = {American Physical Society}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close https://link.aps.org/doi/10.1103/PhysRevB.110.094424 doi:10.1103/PhysRevB.110.094424 Close
14.	Shashank Shekhar, Sławomir Mielcarek, Y Otani, Bivas Rana, Aleksandra Trzaskowska Effect of the underlayer on the elastic parameters of the CoFeB/MgO heterostructures Scientific Reports, 14 (1), pp. 20259, 2024, ISSN: 2045-2322. Abstract \| Links \| BibTeX @article{shekhar_effect_2024, title = {Effect of the underlayer on the elastic parameters of the CoFeB/MgO heterostructures}, author = {Shashank Shekhar and Sławomir Mielcarek and Y Otani and Bivas Rana and Aleksandra Trzaskowska}, url = {https://www.nature.com/articles/s41598-024-71110-1}, doi = {10.1038/s41598-024-71110-1}, issn = {2045-2322}, year = {2024}, date = {2024-08-31}, urldate = {2024-09-12}, journal = {Scientific Reports}, volume = {14}, number = {1}, pages = {20259}, abstract = {We investigated the thermally induced surface acoustic waves in CoFeB/MgO heterostructures with different underlayer materials. Our results show a direct correlation between the density and elastic parameters of the underlayer materials and the surface phonon dispersion. Using finite element method-based simulations, we calculate the effective elastic parameters (such as elastic tensor, Young’s modulus, and Poisson’s ratio) for multilayers with different underlayer materials. The simulation results, either considering the elastic parameters of individual layers or considering the effective elastic parameters of whole stacks, exhibit good agreement with the experimental data. This study will help us deepen our understanding of phonon properties and their interactions with other quasiparticles or magnetic textures with the help of these estimated elastic properties.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close We investigated the thermally induced surface acoustic waves in CoFeB/MgO heterostructures with different underlayer materials. Our results show a direct correlation between the density and elastic parameters of the underlayer materials and the surface phonon dispersion. Using finite element method-based simulations, we calculate the effective elastic parameters (such as elastic tensor, Young’s modulus, and Poisson’s ratio) for multilayers with different underlayer materials. The simulation results, either considering the elastic parameters of individual layers or considering the effective elastic parameters of whole stacks, exhibit good agreement with the experimental data. This study will help us deepen our understanding of phonon properties and their interactions with other quasiparticles or magnetic textures with the help of these estimated elastic properties. Close https://www.nature.com/articles/s41598-024-71110-1 doi:10.1038/s41598-024-71110-1 Close
13.	Riya Mehta, Bivas Rana, Susmita Saha Magnetization dynamics in quasiperiodic magnonic crystals Journal of Physics: Condensed Matter, 36 (44), pp. 443003, 2024. Abstract \| Links \| BibTeX @article{Mehta_2024, title = {Magnetization dynamics in quasiperiodic magnonic crystals}, author = {Riya Mehta and Bivas Rana and Susmita Saha}, url = {https://dx.doi.org/10.1088/1361-648X/ad5ee8}, doi = {10.1088/1361-648X/ad5ee8}, year = {2024}, date = {2024-08-01}, journal = {Journal of Physics: Condensed Matter}, volume = {36}, number = {44}, pages = {443003}, publisher = {IOP Publishing}, abstract = {Quasiperiodic magnonic crystals, in contrast to their periodic counterparts, lack strict periodicity which gives rise to complex and localised spin wave spectra characterized by numerous band gaps and fractal features. Despite their intrinsic structural complexity, quasiperiodic nature of these magnonic crystals enables better tunability of spin wave spectra over their periodic counterparts and therefore holds promise for the applications in reprogrammable magnonic devices. In this article, we provide an overview of magnetization reversal and precessional magnetization dynamics studied so far in various quasiperiodic magnonic crystals, illustrating how their quasiperiodic nature gives rise to tailored band structure, enabling unparalleled control over spin waves. The review is concluded by highlighting the possible potential applications of these quasiperiodic magnonic crystals, exploring potential avenues for future exploration followed by a brief summary.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Quasiperiodic magnonic crystals, in contrast to their periodic counterparts, lack strict periodicity which gives rise to complex and localised spin wave spectra characterized by numerous band gaps and fractal features. Despite their intrinsic structural complexity, quasiperiodic nature of these magnonic crystals enables better tunability of spin wave spectra over their periodic counterparts and therefore holds promise for the applications in reprogrammable magnonic devices. In this article, we provide an overview of magnetization reversal and precessional magnetization dynamics studied so far in various quasiperiodic magnonic crystals, illustrating how their quasiperiodic nature gives rise to tailored band structure, enabling unparalleled control over spin waves. The review is concluded by highlighting the possible potential applications of these quasiperiodic magnonic crystals, exploring potential avenues for future exploration followed by a brief summary. Close https://dx.doi.org/10.1088/1361-648X/ad5ee8 Close
12.	Benedetta Flebus, Dirk Grundler, Bivas Rana, YoshiChika Otani, Igor Barsukov, Anjan Barman, Gianluca Gubbiotti, Pedro Landeros, Johan Akerman, Ursula Ebels, Philipp Pirro, Vladislav E Demidov, Katrin Schultheiss, Gyorgy Csaba, Qi Wang, Florin Ciubotaru, Dmitri E Nikonov, Ping Che, Riccardo Hertel, Teruo Ono, Dmytro Afanasiev, Johan Mentink, Theo Rasing, Burkard Hillebrands, Silvia Viola Kusminskiy, Wei Zhang, Chunhui Rita Du, Aurore Finco, Toeno van der Sar, Yunqiu Kelly Luo, Yoichi Shiota, Joseph Sklenar, Tao Yu, Jinwei Rao The 2024 magnonics roadmap Journal of Physics: Condensed Matter, 36 (36), pp. 363501, 2024. Abstract \| Links \| BibTeX @article{Flebus_2024, title = {The 2024 magnonics roadmap}, author = {Benedetta Flebus and Dirk Grundler and Bivas Rana and YoshiChika Otani and Igor Barsukov and Anjan Barman and Gianluca Gubbiotti and Pedro Landeros and Johan Akerman and Ursula Ebels and Philipp Pirro and Vladislav E Demidov and Katrin Schultheiss and Gyorgy Csaba and Qi Wang and Florin Ciubotaru and Dmitri E Nikonov and Ping Che and Riccardo Hertel and Teruo Ono and Dmytro Afanasiev and Johan Mentink and Theo Rasing and Burkard Hillebrands and Silvia Viola Kusminskiy and Wei Zhang and Chunhui Rita Du and Aurore Finco and Toeno van der Sar and Yunqiu Kelly Luo and Yoichi Shiota and Joseph Sklenar and Tao Yu and Jinwei Rao}, url = {`}, doi = {10.1088/1361-648X/ad399c}, year = {2024}, date = {2024-06-14}, journal = {Journal of Physics: Condensed Matter}, volume = {36}, number = {36}, pages = {363501}, publisher = {IOP Publishing}, abstract = {Magnonics is a research field that has gained an increasing interest in both the fundamental and applied sciences in recent years. This field aims to explore and functionalize collective spin excitations in magnetically ordered materials for modern information technologies, sensing applications and advanced computational schemes. Spin waves, also known as magnons, carry spin angular momenta that allow for the transmission, storage and processing of information without moving charges. In integrated circuits, magnons enable on-chip data processing at ultrahigh frequencies without the Joule heating, which currently limits clock frequencies in conventional data processors to a few GHz. Recent developments in the field indicate that functional magnonic building blocks for in-memory computation, neural networks and Ising machines are within reach. At the same time, the miniaturization of magnonic circuits advances continuously as the synergy of materials science, electrical engineering and nanotechnology allows for novel on-chip excitation and detection schemes. Such circuits can already enable magnon wavelengths of 50 nm at microwave frequencies in a 5G frequency band. Research into non-charge-based technologies is urgently needed in view of the rapid growth of machine learning and artificial intelligence applications, which consume substantial energy when implemented on conventional data processing units. In its first part, the 2024 Magnonics Roadmap provides an update on the recent developments and achievements in the field of nano-magnonics while defining its future avenues and challenges. In its second part, the Roadmap addresses the rapidly growing research endeavors on hybrid structures and magnonics-enabled quantum engineering. We anticipate that these directions will continue to attract researchers to the field and, in addition to showcasing intriguing science, will enable unprecedented functionalities that enhance the efficiency of alternative information technologies and computational schemes.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Magnonics is a research field that has gained an increasing interest in both the fundamental and applied sciences in recent years. This field aims to explore and functionalize collective spin excitations in magnetically ordered materials for modern information technologies, sensing applications and advanced computational schemes. Spin waves, also known as magnons, carry spin angular momenta that allow for the transmission, storage and processing of information without moving charges. In integrated circuits, magnons enable on-chip data processing at ultrahigh frequencies without the Joule heating, which currently limits clock frequencies in conventional data processors to a few GHz. Recent developments in the field indicate that functional magnonic building blocks for in-memory computation, neural networks and Ising machines are within reach. At the same time, the miniaturization of magnonic circuits advances continuously as the synergy of materials science, electrical engineering and nanotechnology allows for novel on-chip excitation and detection schemes. Such circuits can already enable magnon wavelengths of 50 nm at microwave frequencies in a 5G frequency band. Research into non-charge-based technologies is urgently needed in view of the rapid growth of machine learning and artificial intelligence applications, which consume substantial energy when implemented on conventional data processing units. In its first part, the 2024 Magnonics Roadmap provides an update on the recent developments and achievements in the field of nano-magnonics while defining its future avenues and challenges. In its second part, the Roadmap addresses the rapidly growing research endeavors on hybrid structures and magnonics-enabled quantum engineering. We anticipate that these directions will continue to attract researchers to the field and, in addition to showcasing intriguing science, will enable unprecedented functionalities that enhance the efficiency of alternative information technologies and computational schemes. Close ` doi:10.1088/1361-648X/ad399c Close
2023
11.	Bivas Rana, YoshiChika Otani Anisotropy of magnetic damping in Ta/CoFeB/MgO heterostructures Scientific Reports, 13 (1), pp. 8532, 2023, ISSN: 2045-2322. Abstract \| Links \| BibTeX @article{rana_anisotropy_2023, title = {Anisotropy of magnetic damping in Ta/CoFeB/MgO heterostructures}, author = {Bivas Rana and YoshiChika Otani}, url = {https://www.nature.com/articles/s41598-023-35739-8}, doi = {10.1038/s41598-023-35739-8}, issn = {2045-2322}, year = {2023}, date = {2023-05-26}, urldate = {2023-05-28}, journal = {Scientific Reports}, volume = {13}, number = {1}, pages = {8532}, abstract = {Magnetic damping controls the performance and operational speed of many spintronics devices. Being a tensor quantity, the damping in magnetic thin films often shows anisotropic behavior with the magnetization orientation. Here, we have studied the anisotropy of damping in Ta/CoFeB/MgO heterostructures, deposited on thermally oxidized Si substrates, as a function of the orientation of magnetization. By performing ferromagnetic resonance (FMR) measurements based on spin pumping and inverse spin Hall effect (ISHE), we extract the damping parameter in those films and find that the anisotropy of damping contains four-fold and two-fold anisotropy terms. We infer that four-fold anisotropy originates from two-magnon scattering (TMS). By studying reference Ta/CoFeB/MgO films, deposited on LiNbO3 substrates, we find that the two-fold anisotropy is correlated with in-plane magnetic anisotropy (IMA) of the films, suggesting its origin as the anisotropy in bulk spin–orbit coupling (SOC) of CoFeB film. We conclude that when IMA is very small, it’s correlation with two-fold anisotropy cannot be experimentally identified. However, as IMA increases, it starts to show a correlation with two-fold anisotropy in damping. These results will be beneficial for designing future spintronics devices.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Magnetic damping controls the performance and operational speed of many spintronics devices. Being a tensor quantity, the damping in magnetic thin films often shows anisotropic behavior with the magnetization orientation. Here, we have studied the anisotropy of damping in Ta/CoFeB/MgO heterostructures, deposited on thermally oxidized Si substrates, as a function of the orientation of magnetization. By performing ferromagnetic resonance (FMR) measurements based on spin pumping and inverse spin Hall effect (ISHE), we extract the damping parameter in those films and find that the anisotropy of damping contains four-fold and two-fold anisotropy terms. We infer that four-fold anisotropy originates from two-magnon scattering (TMS). By studying reference Ta/CoFeB/MgO films, deposited on LiNbO3 substrates, we find that the two-fold anisotropy is correlated with in-plane magnetic anisotropy (IMA) of the films, suggesting its origin as the anisotropy in bulk spin–orbit coupling (SOC) of CoFeB film. We conclude that when IMA is very small, it’s correlation with two-fold anisotropy cannot be experimentally identified. However, as IMA increases, it starts to show a correlation with two-fold anisotropy in damping. These results will be beneficial for designing future spintronics devices. Close https://www.nature.com/articles/s41598-023-35739-8 doi:10.1038/s41598-023-35739-8 Close
10.	J M Flores-Camacho, Bivas Rana, R E Balderas-Navarro, A Lastras-Martínez, Yoshichika Otani, Jorge Puebla Mid-infrared optical properties of non-magnetic-metal/CoFeB/MgO heterostructures Journal of Physics D: Applied Physics, 56 (31), pp. 315301, 2023. Abstract \| Links \| BibTeX @article{Flores-Camacho_2023, title = {Mid-infrared optical properties of non-magnetic-metal/CoFeB/MgO heterostructures}, author = {J M Flores-Camacho and Bivas Rana and R E Balderas-Navarro and A Lastras-Martínez and Yoshichika Otani and Jorge Puebla}, url = {https://dx.doi.org/10.1088/1361-6463/acd00f}, doi = {10.1088/1361-6463/acd00f}, year = {2023}, date = {2023-05-09}, journal = {Journal of Physics D: Applied Physics}, volume = {56}, number = {31}, pages = {315301}, publisher = {IOP Publishing}, abstract = {We report on the optical characterization of non-magnetic metal (NM)/ferromagnetic (Co20Fe60B20)/MgO heterostructures and interfaces by using mid infrared (MIR) spectroscopic ellipsometry at room temperature. We extracted for the MIR range the dielectric function (DF) of Co20Fe60B20, that is lacking in literature, from a multisample analysis. From the optical modeling of the heterostructures we detected and determined the dielectric tensor properties of a two-dimensional electron gas (2DEG) forming at the NM and the CoFeB interface. These properties comprise independent Drude parameters for the in-plane and out-of plane tensor components, with the latter having an epsilon-near-zero frequency within our working spectral range. A feature assigned to spin–orbit coupling (SOC) is identified. Furthermore, it is found that both, the interfacial properties, 2DEG Drude parameters and SOC strength, and the apparent DF of the MgO layer depend on the type of the underlying NM, namely, Pt, W, or Cu. The results reported here should be useful in tailoring novel phenomena in such types of heterostructures by assessing their optical response noninvasively, complementing existing characterization tools such as angle-resolved photoemission spectroscopy, and those related to electron/spin transport.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close We report on the optical characterization of non-magnetic metal (NM)/ferromagnetic (Co20Fe60B20)/MgO heterostructures and interfaces by using mid infrared (MIR) spectroscopic ellipsometry at room temperature. We extracted for the MIR range the dielectric function (DF) of Co20Fe60B20, that is lacking in literature, from a multisample analysis. From the optical modeling of the heterostructures we detected and determined the dielectric tensor properties of a two-dimensional electron gas (2DEG) forming at the NM and the CoFeB interface. These properties comprise independent Drude parameters for the in-plane and out-of plane tensor components, with the latter having an epsilon-near-zero frequency within our working spectral range. A feature assigned to spin–orbit coupling (SOC) is identified. Furthermore, it is found that both, the interfacial properties, 2DEG Drude parameters and SOC strength, and the apparent DF of the MgO layer depend on the type of the underlying NM, namely, Pt, W, or Cu. The results reported here should be useful in tailoring novel phenomena in such types of heterostructures by assessing their optical response noninvasively, complementing existing characterization tools such as angle-resolved photoemission spectroscopy, and those related to electron/spin transport. Close https://dx.doi.org/10.1088/1361-6463/acd00f Close
9.	Angshuman Deka, Bivas Rana, YoshiChika Otani, Yasuhiro Fukuma Ferromagnetic resonance excited by interfacial microwave electric field: the role of current-induced torques Journal of Physics: Condensed Matter, 35 (21), pp. 214003, 2023. Abstract \| Links \| BibTeX @article{Deka_2023, title = {Ferromagnetic resonance excited by interfacial microwave electric field: the role of current-induced torques}, author = {Angshuman Deka and Bivas Rana and YoshiChika Otani and Yasuhiro Fukuma}, url = {https://dx.doi.org/10.1088/1361-648X/acc377}, doi = {10.1088/1361-648X/acc377}, year = {2023}, date = {2023-03-24}, journal = {Journal of Physics: Condensed Matter}, volume = {35}, number = {21}, pages = {214003}, publisher = {IOP Publishing}, abstract = {Excitation of magnetization dynamics in magnetic materials, especially in ultrathin ferromagnetic films, is of utmost importance for developing various ultrafast spintronics devices. Recently, the excitation of magnetization dynamics, i.e. ferromagnetic resonance (FMR) via electric field-induced modulation of interfacial magnetic anisotropies, has received particular attention due to several advantages, including lower power consumption. However, several additional torques generated by unavoidable microwave current induced because of the capacitive nature of the junctions may also contribute to the excitation of FMR apart from electric field-induced torques. Here, we study the FMR signals excited by applying microwave signal across the metal-oxide junction in CoFeB/MgO heterostructures with Pt and Ta buffer layers. Analysis of the resonance line shape and angular dependent behavior of resonance amplitude revealed that apart from voltage-controlled in-plane magnetic anisotropy (VC-IMA) torque a significant contribution can also arises from spin-torques and Oersted field torques originating from the flow of microwave current through metal-oxide junction. Surprisingly, the overall contribution from spin-torques and Oersted field torques are comparable to the VC-IMA torque contribution, even for a device with negligible defects. This study will be beneficial for designing future electric field-controlled spintronics devices.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Excitation of magnetization dynamics in magnetic materials, especially in ultrathin ferromagnetic films, is of utmost importance for developing various ultrafast spintronics devices. Recently, the excitation of magnetization dynamics, i.e. ferromagnetic resonance (FMR) via electric field-induced modulation of interfacial magnetic anisotropies, has received particular attention due to several advantages, including lower power consumption. However, several additional torques generated by unavoidable microwave current induced because of the capacitive nature of the junctions may also contribute to the excitation of FMR apart from electric field-induced torques. Here, we study the FMR signals excited by applying microwave signal across the metal-oxide junction in CoFeB/MgO heterostructures with Pt and Ta buffer layers. Analysis of the resonance line shape and angular dependent behavior of resonance amplitude revealed that apart from voltage-controlled in-plane magnetic anisotropy (VC-IMA) torque a significant contribution can also arises from spin-torques and Oersted field torques originating from the flow of microwave current through metal-oxide junction. Surprisingly, the overall contribution from spin-torques and Oersted field torques are comparable to the VC-IMA torque contribution, even for a device with negligible defects. This study will be beneficial for designing future electric field-controlled spintronics devices. Close https://dx.doi.org/10.1088/1361-648X/acc377 Close
8.	Shashank Shekhar, Sławomir Mielcarek, Y Otani, Bivas Rana, Aleksandra Trzaskowska Influence of CoFeB layer thickness on elastic parameters in CoFeB/MgO heterostructures Scientific Reports, 13 (1), pp. 10668, 2023, ISSN: 2045-2322. Abstract \| Links \| BibTeX @article{shekhar_influence_2023, title = {Influence of CoFeB layer thickness on elastic parameters in CoFeB/MgO heterostructures}, author = {Shashank Shekhar and Sławomir Mielcarek and Y Otani and Bivas Rana and Aleksandra Trzaskowska}, url = {https://www.nature.com/articles/s41598-023-37808-4}, doi = {10.1038/s41598-023-37808-4}, issn = {2045-2322}, year = {2023}, date = {2023-01-01}, urldate = {2023-07-04}, journal = {Scientific Reports}, volume = {13}, number = {1}, pages = {10668}, abstract = {The surface acoustic waves, i.e., surface phonons may have huge potential for future spintronic devices, if coupled to other waves (e.g., spin waves) or quasiparticles. In order to understand the coupling of acoustic phonons with the spin degree of freedom, especially in magnetic thin film-based heterostructures, one needs to investigate the properties of phonons in those heterostructures. This also allows us to determine the elastic properties of individual magnetic layers and the effective elastic parameters of the whole stacks. Here, we study frequency versus wavevector dispersion of thermally excited SAWs in CoFeB/MgO heterostructures with varying CoFeB thickness by employing Brillouin light spectroscopy. The experimental results are corroborated by finite element method-based simulations. From the best agreement of simulation results with the experiments, we find out the elastic tensor parameters for CoFeB layer. Additionally, we estimate the effective elastic parameters (elastic tensors, Young’s modulus, Poisson’s ratio) of the whole stacks for varying CoFeB thickness. Interestingly, the simulation results, either considering elastic parameters of individual layers or considering effective elastic parameters of whole stacks, show good agreement with the experimental results. These extracted elastic parameters will be very useful to understand the interaction of phonons with other quasiparticles.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close The surface acoustic waves, i.e., surface phonons may have huge potential for future spintronic devices, if coupled to other waves (e.g., spin waves) or quasiparticles. In order to understand the coupling of acoustic phonons with the spin degree of freedom, especially in magnetic thin film-based heterostructures, one needs to investigate the properties of phonons in those heterostructures. This also allows us to determine the elastic properties of individual magnetic layers and the effective elastic parameters of the whole stacks. Here, we study frequency versus wavevector dispersion of thermally excited SAWs in CoFeB/MgO heterostructures with varying CoFeB thickness by employing Brillouin light spectroscopy. The experimental results are corroborated by finite element method-based simulations. From the best agreement of simulation results with the experiments, we find out the elastic tensor parameters for CoFeB layer. Additionally, we estimate the effective elastic parameters (elastic tensors, Young’s modulus, Poisson’s ratio) of the whole stacks for varying CoFeB thickness. Interestingly, the simulation results, either considering elastic parameters of individual layers or considering effective elastic parameters of whole stacks, show good agreement with the experimental results. These extracted elastic parameters will be very useful to understand the interaction of phonons with other quasiparticles. Close https://www.nature.com/articles/s41598-023-37808-4 doi:10.1038/s41598-023-37808-4 Close
2022
7.	Tomoyuki Yokouchi, Satoshi Sugimoto, Bivas Rana, Shinichiro Seki, Naoki Ogawa, Yuki Shiomi, Shinya Kasai, Yoshichika Otani Pattern recognition with neuromorphic computing using magnetic field-induced dynamics of skyrmions Science Advances, 8 (39), pp. eabq5652, 2022. Abstract \| Links \| BibTeX @article{doi:10.1126/sciadv.abq5652, title = {Pattern recognition with neuromorphic computing using magnetic field-induced dynamics of skyrmions}, author = {Tomoyuki Yokouchi and Satoshi Sugimoto and Bivas Rana and Shinichiro Seki and Naoki Ogawa and Yuki Shiomi and Shinya Kasai and Yoshichika Otani}, url = {https://www.science.org/doi/pdf/10.1126/sciadv.abq5652}, doi = {10.1126/sciadv.abq5652}, year = {2022}, date = {2022-09-30}, journal = {Science Advances}, volume = {8}, number = {39}, pages = {eabq5652}, abstract = {Nonlinear phenomena in physical systems can be used for brain-inspired computing with low energy consumption. Response from the dynamics of a topological spin structure called skyrmion is one of the candidates for such a neuromorphic computing. However, its ability has not been well explored experimentally. Here, we experimentally demonstrate neuromorphic computing using nonlinear response originating from magnetic field–induced dynamics of skyrmions. We designed a simple-structured skyrmion-based neuromorphic device and succeeded in handwritten digit recognition with the accuracy as large as 94.7% and waveform recognition. Notably, there exists a positive correlation between the recognition accuracy and the number of skyrmions in the devices. The large degrees of freedom of skyrmion systems, such as the position and the size, originate from the more complex nonlinear mapping, the larger output dimension, and, thus, high accuracy. Our results provide a guideline for developing energy-saving and high-performance skyrmion neuromorphic computing devices. Skyrmion-based neuromorphic computing device recognizes waveforms and handwritten digits with high accuracy.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Nonlinear phenomena in physical systems can be used for brain-inspired computing with low energy consumption. Response from the dynamics of a topological spin structure called skyrmion is one of the candidates for such a neuromorphic computing. However, its ability has not been well explored experimentally. Here, we experimentally demonstrate neuromorphic computing using nonlinear response originating from magnetic field–induced dynamics of skyrmions. We designed a simple-structured skyrmion-based neuromorphic device and succeeded in handwritten digit recognition with the accuracy as large as 94.7% and waveform recognition. Notably, there exists a positive correlation between the recognition accuracy and the number of skyrmions in the devices. The large degrees of freedom of skyrmion systems, such as the position and the size, originate from the more complex nonlinear mapping, the larger output dimension, and, thus, high accuracy. Our results provide a guideline for developing energy-saving and high-performance skyrmion neuromorphic computing devices. Skyrmion-based neuromorphic computing device recognizes waveforms and handwritten digits with high accuracy. Close https://www.science.org/doi/pdf/10.1126/sciadv.abq5652 doi:10.1126/sciadv.abq5652 Close
6.	Surya Narayan Panda, Bivas Rana, YoshiChika Otani, Anjan Barman Role of Spin–Orbit Coupling on Ultrafast Spin Dynamics in Nonmagnet/Ferromagnet Heterostructures Advanced Quantum Technologies, 2022 , pp. 2200016, 2022. Abstract \| Links \| BibTeX @article{https://doi.org/10.1002/qute.202200016, title = {Role of Spin–Orbit Coupling on Ultrafast Spin Dynamics in Nonmagnet/Ferromagnet Heterostructures}, author = {Surya Narayan Panda and Bivas Rana and YoshiChika Otani and Anjan Barman}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/qute.202200016}, doi = {https://doi.org/10.1002/qute.202200016}, year = {2022}, date = {2022-07-01}, journal = {Advanced Quantum Technologies}, volume = {2022}, pages = {2200016}, abstract = {Abstract Spin–orbit coupling (SOC), the interaction between spin and orbital angular momentum of electrons, is imperative to control magnetic properties of nonmagnet (NM)/ferromagnet (FM) heterostructures and design energy-efficient and faster spin-based devices. Here, femtosecond pulsed laser-induced time-resolved magneto-optical Kerr effect magnetometry is employed to investigate magnetization dynamics in different NM/Co20Fe60B20 heterostructures, where the NM layer varies as Cu, Ta, W, Pt, Ta/Ru/Ta, and Si/SiO2 (no underlayer) that differ in SOC strength. It is observed that there is a systematic variation in ultrafast demagnetization time (τm), fast remagnetization time (τr), and Gilbert damping parameter (α) with the SOC strength of the underlayer and an inverse relationship between α and τm, τr is established due to the dominant contribution of spin current transport in ultrafast demagnetization and fast remagnetization processes. The spin pumping formalism estimates the effective spin-mixing conductance (Geff) for different interfaces, which signifies that the high SOC strength of underlayers results in high Geff indicating more efficient transport of spin current through it. This study suggests that the SOC strength of the NM underlayer plays a significant role in controlling the ultrafast demagnetization process through interfacial spin current transport in a NM/FM heterostructure which can be beneficial for the development of ultrafast spintronics devices.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Abstract Spin–orbit coupling (SOC), the interaction between spin and orbital angular momentum of electrons, is imperative to control magnetic properties of nonmagnet (NM)/ferromagnet (FM) heterostructures and design energy-efficient and faster spin-based devices. Here, femtosecond pulsed laser-induced time-resolved magneto-optical Kerr effect magnetometry is employed to investigate magnetization dynamics in different NM/Co20Fe60B20 heterostructures, where the NM layer varies as Cu, Ta, W, Pt, Ta/Ru/Ta, and Si/SiO2 (no underlayer) that differ in SOC strength. It is observed that there is a systematic variation in ultrafast demagnetization time (τm), fast remagnetization time (τr), and Gilbert damping parameter (α) with the SOC strength of the underlayer and an inverse relationship between α and τm, τr is established due to the dominant contribution of spin current transport in ultrafast demagnetization and fast remagnetization processes. The spin pumping formalism estimates the effective spin-mixing conductance (Geff) for different interfaces, which signifies that the high SOC strength of underlayers results in high Geff indicating more efficient transport of spin current through it. This study suggests that the SOC strength of the NM underlayer plays a significant role in controlling the ultrafast demagnetization process through interfacial spin current transport in a NM/FM heterostructure which can be beneficial for the development of ultrafast spintronics devices. Close https://onlinelibrary.wiley.com/doi/abs/10.1002/qute.202200016 doi:https://doi.org/10.1002/qute.202200016 Close
5.	Angshuman Deka, Bivas Rana, Ryo Anami, Katsuya Miura, Hiromasa Takahashi, YoshiChika Otani, Yasuhiro Fukuma Electric field induced parametric excitation of exchange magnons in a CoFeB/MgO junction Phys. Rev. Research, 4 , pp. 023139, 2022. Abstract \| Links \| BibTeX @article{PhysRevResearch.4.023139, title = {Electric field induced parametric excitation of exchange magnons in a CoFeB/MgO junction}, author = {Angshuman Deka and Bivas Rana and Ryo Anami and Katsuya Miura and Hiromasa Takahashi and YoshiChika Otani and Yasuhiro Fukuma}, url = {https://link.aps.org/doi/10.1103/PhysRevResearch.4.023139}, doi = {10.1103/PhysRevResearch.4.023139}, year = {2022}, date = {2022-05-20}, journal = {Phys. Rev. Research}, volume = {4}, pages = {023139}, publisher = {American Physical Society}, abstract = {Inspired by the success of field-effect transistors in electronics, electric field controlled magnetization dynamics has emerged as an important integrant in low-power spintronic devices. Here, we demonstrate electric field induced parametric excitation for CoFeB/MgO junctions by using interfacial in-plane magnetic anisotropy (IMA). When the IMA and the external magnetic field are parallel to each other, magnons are efficiently excited by electric field induced parametric resonance. The corresponding wavelengths are estimated to be tuned down to exchange interaction length scales by changing the input power and frequency of the applied voltage. A generalized phenomenological model is developed to explain the underlying role of the electric field torque. Electric field control of IMA is shown to be the origin for excitation of both uniform and parametric resonance modes in the in-plane magnetized sample, a crucial element for purely electric field induced magnetization dynamics. Electric field excitation of exchange magnons, with no Joule heating, offers a good opportunity for developing nanoscale magnonic devices and exploring various nonlinear dynamics in nanomagnetic systems.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Inspired by the success of field-effect transistors in electronics, electric field controlled magnetization dynamics has emerged as an important integrant in low-power spintronic devices. Here, we demonstrate electric field induced parametric excitation for CoFeB/MgO junctions by using interfacial in-plane magnetic anisotropy (IMA). When the IMA and the external magnetic field are parallel to each other, magnons are efficiently excited by electric field induced parametric resonance. The corresponding wavelengths are estimated to be tuned down to exchange interaction length scales by changing the input power and frequency of the applied voltage. A generalized phenomenological model is developed to explain the underlying role of the electric field torque. Electric field control of IMA is shown to be the origin for excitation of both uniform and parametric resonance modes in the in-plane magnetized sample, a crucial element for purely electric field induced magnetization dynamics. Electric field excitation of exchange magnons, with no Joule heating, offers a good opportunity for developing nanoscale magnonic devices and exploring various nonlinear dynamics in nanomagnetic systems. Close https://link.aps.org/doi/10.1103/PhysRevResearch.4.023139 doi:10.1103/PhysRevResearch.4.023139 Close
4.	A V Chumak, P Kabos, M Wu, C Abert, C Adelmann, A O Adeyeye, J Akerman, F G Aliev, A Anane, A Awad, C H Back, A Barman, G E W Bauer, M Becherer, E N Beginin, V A S V Bittencourt, Y M Blanter, P Bortolotti, I Boventer, D A Bozhko, S A Bunyaev, J J Carmiggelt, R R Cheenikundil, F Ciubotaru, S Cotofana, G Csaba, O V Dobrovolskiy, C Dubs, M Elyasi, K G Fripp, H Fulara, I A Golovchanskiy, C Gonzalez-Ballestero, Piotr Graczyk, D Grundler, Paweł Gruszecki, G Gubbiotti, K Guslienko, A Haldar, S Hamdioui, R Hertel, B Hillebrands, T Hioki, A Houshang, C -M Hu, H Huebl, M Huth, E Iacocca, M B Jungfleisch, G N Kakazei, A Khitun, R Khymyn, T Kikkawa, M Kloui, O Klein, Jarosław W. Kłos, S Knauer, S Koraltan, M Kostylev, Maciej Krawczyk, I N Krivorotov, V V Kruglyak, D Lachance-Quirion, S Ladak, R Lebrun, Y Li, M Lindner, R Macedo, S Mayr, G A Melkov, Szymon Mieszczak, Y Nakamura, H T Nembach, A A Nikitin, S A Nikitov, V Novosad, J A Otalora, Y Otani, A Papp, B Pigeau, P Pirro, W Porod, F Porrati, H Qin, Bivas Rana, T Reimann, F Riente, O Romero-Isart, A Ross, A V Sadovnikov, A R Safin, E Saitoh, G Schmidt, H Schultheiss, K Schultheiss, A A Serga, S Sharma, J M Shaw, D Suess, O Surzhenko, Krzysztof Szulc, T Taniguchi, M Urbanek, K Usami, A B Ustinov, T van der Sar, S van Dijken, V I Vasyuchka, R Verba, Viola S Kusminskiy, Q Wang, M Weides, M Weiler, S Wintz, S P Wolski, X Zhang Advances in Magnetics Roadmap on Spin-Wave Computing IEEE Trans. Magn., 58 (6), pp. 1-72, 2022, ISSN: 1941-0069. Abstract \| Links \| BibTeX @article{9706176, title = {Advances in Magnetics Roadmap on Spin-Wave Computing}, author = {A V Chumak and P Kabos and M Wu and C Abert and C Adelmann and A O Adeyeye and J Akerman and F G Aliev and A Anane and A Awad and C H Back and A Barman and G E W Bauer and M Becherer and E N Beginin and V A S V Bittencourt and Y M Blanter and P Bortolotti and I Boventer and D A Bozhko and S A Bunyaev and J J Carmiggelt and R R Cheenikundil and F Ciubotaru and S Cotofana and G Csaba and O V Dobrovolskiy and C Dubs and M Elyasi and K G Fripp and H Fulara and I A Golovchanskiy and C Gonzalez-Ballestero and Piotr Graczyk and D Grundler and Paweł Gruszecki and G Gubbiotti and K Guslienko and A Haldar and S Hamdioui and R Hertel and B Hillebrands and T Hioki and A Houshang and C -M Hu and H Huebl and M Huth and E Iacocca and M B Jungfleisch and G N Kakazei and A Khitun and R Khymyn and T Kikkawa and M Kloui and O Klein and Jarosław W. Kłos and S Knauer and S Koraltan and M Kostylev and Maciej Krawczyk and I N Krivorotov and V V Kruglyak and D Lachance-Quirion and S Ladak and R Lebrun and Y Li and M Lindner and R Macedo and S Mayr and G A Melkov and Szymon Mieszczak and Y Nakamura and H T Nembach and A A Nikitin and S A Nikitov and V Novosad and J A Otalora and Y Otani and A Papp and B Pigeau and P Pirro and W Porod and F Porrati and H Qin and Bivas Rana and T Reimann and F Riente and O Romero-Isart and A Ross and A V Sadovnikov and A R Safin and E Saitoh and G Schmidt and H Schultheiss and K Schultheiss and A A Serga and S Sharma and J M Shaw and D Suess and O Surzhenko and Krzysztof Szulc and T Taniguchi and M Urbanek and K Usami and A B Ustinov and T van der Sar and S van Dijken and V I Vasyuchka and R Verba and Viola S Kusminskiy and Q Wang and M Weides and M Weiler and S Wintz and S P Wolski and X Zhang}, doi = {10.1109/TMAG.2022.3149664}, issn = {1941-0069}, year = {2022}, date = {2022-02-07}, journal = {IEEE Trans. Magn.}, volume = {58}, number = {6}, pages = {1-72}, abstract = {Magnonics addresses the physical properties of spin waves and utilizes them for data processing. Scalability down to atomic dimensions, operation in the GHz-to-THz frequency range, utilization of nonlinear and nonreciprocal phenomena, and compatibility with CMOS are just a few of many advantages offered by magnons. Although magnonics is still primarily positioned in the academic domain, the scientific and technological challenges of the field are being extensively investigated, and many proof-of-concept prototypes have already been realized in laboratories. This roadmap is a product of the collective work of many authors, which covers versatile spin-wave computing approaches, conceptual building blocks, and underlying physical phenomena. In particular, the roadmap discusses the computation operations with the Boolean digital data, unconventional approaches, such as neuromorphic computing, and the progress toward magnon-based quantum computing. This article is organized as a collection of sub-sections grouped into seven large thematic sections. Each sub-section is prepared by one or a group of authors and concludes with a brief description of current challenges and the outlook of further development for each research direction.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Magnonics addresses the physical properties of spin waves and utilizes them for data processing. Scalability down to atomic dimensions, operation in the GHz-to-THz frequency range, utilization of nonlinear and nonreciprocal phenomena, and compatibility with CMOS are just a few of many advantages offered by magnons. Although magnonics is still primarily positioned in the academic domain, the scientific and technological challenges of the field are being extensively investigated, and many proof-of-concept prototypes have already been realized in laboratories. This roadmap is a product of the collective work of many authors, which covers versatile spin-wave computing approaches, conceptual building blocks, and underlying physical phenomena. In particular, the roadmap discusses the computation operations with the Boolean digital data, unconventional approaches, such as neuromorphic computing, and the progress toward magnon-based quantum computing. This article is organized as a collection of sub-sections grouped into seven large thematic sections. Each sub-section is prepared by one or a group of authors and concludes with a brief description of current challenges and the outlook of further development for each research direction. Close doi:10.1109/TMAG.2022.3149664 Close
2021
3.	Bivas Rana, Amrit Kumar Mondal, Supriyo Bandyopadhyay, Anjan Barman Applications of nanomagnets as dynamical systems - part II Nanotechnology, 33 (8), pp. 082002, 2021. Abstract \| Links \| BibTeX @article{Rana_2021b, title = {Applications of nanomagnets as dynamical systems - part II}, author = {Bivas Rana and Amrit Kumar Mondal and Supriyo Bandyopadhyay and Anjan Barman}, url = {https://doi.org/10.1088/1361-6528/ac2f59}, doi = {10.1088/1361-6528/ac2f59}, year = {2021}, date = {2021-11-30}, journal = {Nanotechnology}, volume = {33}, number = {8}, pages = {082002}, publisher = {IOP Publishing}, abstract = {In Part I of this topical review, we discussed dynamical phenomena in nanomagnets, focusing primarily on magnetization reversal with an eye to digital applications. In this part, we address mostly wave-like phenomena in nanomagnets, with emphasis on spin waves in myriad nanomagnetic systems and methods of controlling magnetization dynamics in nanomagnet arrays which may have analog applications. We conclude with a discussion of some interesting spintronic phenomena that undergird the rich physics exhibited by nanomagnet assemblies.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close In Part I of this topical review, we discussed dynamical phenomena in nanomagnets, focusing primarily on magnetization reversal with an eye to digital applications. In this part, we address mostly wave-like phenomena in nanomagnets, with emphasis on spin waves in myriad nanomagnetic systems and methods of controlling magnetization dynamics in nanomagnet arrays which may have analog applications. We conclude with a discussion of some interesting spintronic phenomena that undergird the rich physics exhibited by nanomagnet assemblies. Close https://doi.org/10.1088/1361-6528/ac2f59 doi:10.1088/1361-6528/ac2f59 Close
2.	Bivas Rana, Amrit Kumar Mondal, Supriyo Bandyopadhyay, Anjan Barman Applications of nanomagnets as dynamical systems - part I Nanotechnology, 33 (6), pp. 062007, 2021. Abstract \| Links \| BibTeX @article{Rana_2021, title = {Applications of nanomagnets as dynamical systems - part I}, author = {Bivas Rana and Amrit Kumar Mondal and Supriyo Bandyopadhyay and Anjan Barman}, url = {https://doi.org/10.1088/1361-6528/ac2e75}, doi = {10.1088/1361-6528/ac2e75}, year = {2021}, date = {2021-11-19}, journal = {Nanotechnology}, volume = {33}, number = {6}, pages = {062007}, publisher = {IOP Publishing}, abstract = {When magnets are fashioned into nanoscale elements, they exhibit a wide variety of phenomena replete with rich physics and the lure of tantalizing applications. In this topical review, we discuss some of these phenomena, especially those that have come to light recently, and highlight their potential applications. We emphasize what drives a phenomenon, what undergirds the dynamics of the system that exhibits the phenomenon, how the dynamics can be manipulated, and what specific features can be harnessed for technological advances. For the sake of balance, we point out both advantages and shortcomings of nanomagnet based devices and systems predicated on the phenomena we discuss. Where possible, we chart out paths for future investigations that can shed new light on an intriguing phenomenon and/or facilitate both traditional and non-traditional applications.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close When magnets are fashioned into nanoscale elements, they exhibit a wide variety of phenomena replete with rich physics and the lure of tantalizing applications. In this topical review, we discuss some of these phenomena, especially those that have come to light recently, and highlight their potential applications. We emphasize what drives a phenomenon, what undergirds the dynamics of the system that exhibits the phenomenon, how the dynamics can be manipulated, and what specific features can be harnessed for technological advances. For the sake of balance, we point out both advantages and shortcomings of nanomagnet based devices and systems predicated on the phenomena we discuss. Where possible, we chart out paths for future investigations that can shed new light on an intriguing phenomenon and/or facilitate both traditional and non-traditional applications. Close https://doi.org/10.1088/1361-6528/ac2e75 doi:10.1088/1361-6528/ac2e75 Close
1.	Anjan Barman, Gianluca Gubbiotti, S Ladak, A O Adeyeye, Maciej Krawczyk, J Gräfe, C Adelmann, S Cotofana, A Naeemi, V I Vasyuchka, B Hillebrands, S A Nikitov, H Yu, D Grundler, A V Sadovnikov, A A Grachev, S E Sheshukova, J-Y Duquesne, M Marangolo, G Csaba, W Porod, V E Demidov, S Urazhdin, S O Demokritov, E Albisetti, D Petti, R Bertacco, H Schultheiss, V V Kruglyak, V D Poimanov, S Sahoo, J Sinha, H Yang, M Münzenberg, T Moriyama, S Mizukami, P Landeros, R A Gallardo, G Carlotti, J-V Kim, R L Stamps, R E Camley, Bivas Rana, Y Otani, W Yu, T Yu, G E W Bauer, C Back, G S Uhrig, O V Dobrovolskiy, B Budinska, H Qin, S van Dijken, A V Chumak, A Khitun, D E Nikonov, I A Young, B W Zingsem, M Winklhofer The 2021 Magnonics Roadmap Journal of Physics: Condensed Matter, 33 (41), pp. 413001, 2021. Abstract \| Links \| BibTeX @article{Barman_2021, title = {The 2021 Magnonics Roadmap}, author = {Anjan Barman and Gianluca Gubbiotti and S Ladak and A O Adeyeye and Maciej Krawczyk and J Gräfe and C Adelmann and S Cotofana and A Naeemi and V I Vasyuchka and B Hillebrands and S A Nikitov and H Yu and D Grundler and A V Sadovnikov and A A Grachev and S E Sheshukova and J-Y Duquesne and M Marangolo and G Csaba and W Porod and V E Demidov and S Urazhdin and S O Demokritov and E Albisetti and D Petti and R Bertacco and H Schultheiss and V V Kruglyak and V D Poimanov and S Sahoo and J Sinha and H Yang and M Münzenberg and T Moriyama and S Mizukami and P Landeros and R A Gallardo and G Carlotti and J-V Kim and R L Stamps and R E Camley and Bivas Rana and Y Otani and W Yu and T Yu and G E W Bauer and C Back and G S Uhrig and O V Dobrovolskiy and B Budinska and H Qin and S van Dijken and A V Chumak and A Khitun and D E Nikonov and I A Young and B W Zingsem and M Winklhofer}, url = {https://doi.org/10.1088/1361-648x/abec1a}, doi = {10.1088/1361-648x/abec1a}, year = {2021}, date = {2021-08-18}, journal = {Journal of Physics: Condensed Matter}, volume = {33}, number = {41}, pages = {413001}, publisher = {IOP Publishing}, abstract = {Magnonics is a budding research field in nanomagnetism and nanoscience that addresses the use of spin waves (magnons) to transmit, store, and process information. The rapid advancements of this field during last one decade in terms of upsurge in research papers, review articles, citations, proposals of devices as well as introduction of new sub-topics prompted us to present the first roadmap on magnonics. This is a collection of 22 sections written by leading experts in this field who review and discuss the current status besides presenting their vision of future perspectives. Today, the principal challenges in applied magnonics are the excitation of sub-100 nm wavelength magnons, their manipulation on the nanoscale and the creation of sub-micrometre devices using low-Gilbert damping magnetic materials and its interconnections to standard electronics. To this end, magnonics offers lower energy consumption, easier integrability and compatibility with CMOS structure, reprogrammability, shorter wavelength, smaller device features, anisotropic properties, negative group velocity, non-reciprocity and efficient tunability by various external stimuli to name a few. Hence, despite being a young research field, magnonics has come a long way since its early inception. This roadmap asserts a milestone for future emerging research directions in magnonics, and hopefully, it will inspire a series of exciting new articles on the same topic in the coming years.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Magnonics is a budding research field in nanomagnetism and nanoscience that addresses the use of spin waves (magnons) to transmit, store, and process information. The rapid advancements of this field during last one decade in terms of upsurge in research papers, review articles, citations, proposals of devices as well as introduction of new sub-topics prompted us to present the first roadmap on magnonics. This is a collection of 22 sections written by leading experts in this field who review and discuss the current status besides presenting their vision of future perspectives. Today, the principal challenges in applied magnonics are the excitation of sub-100 nm wavelength magnons, their manipulation on the nanoscale and the creation of sub-micrometre devices using low-Gilbert damping magnetic materials and its interconnections to standard electronics. To this end, magnonics offers lower energy consumption, easier integrability and compatibility with CMOS structure, reprogrammability, shorter wavelength, smaller device features, anisotropic properties, negative group velocity, non-reciprocity and efficient tunability by various external stimuli to name a few. Hence, despite being a young research field, magnonics has come a long way since its early inception. This roadmap asserts a milestone for future emerging research directions in magnonics, and hopefully, it will inspire a series of exciting new articles on the same topic in the coming years. Close https://doi.org/10.1088/1361-648x/abec1a doi:10.1088/1361-648x/abec1a Close