@article{Rudziński2024,
title = {Spin waves in bilayers of transition metal dichalcogenides},
author = {Wojciech Rudziński and Józef Barnaś and Anna Dyrdał},
url = {https://journals.aps.org/prb/abstract/10.1103/PhysRevB.109.035412},
doi = {10.1103/PhysRevB.109.035412},
year = {2024},
date = {2024-01-11},
journal = {Physical Review B},
volume = {109},
pages = {035412},
abstract = {Van der Waals magnetic materials are currently of great interest as materials for applications in future ultrathin nanoelectronics and nanospintronics. Due to weak coupling between individual monolayers, these materials can be easily obtained in the monolayer and bilayer forms. The latter are of specific interest as they may be considered as natural two-dimensional spin valves. In this paper, we theoretically study spin waves in bilayers of transition metal dichalcogenides. The considerations are carried within the general spin wave theory based on effective spin Hamiltonian and Holstein-Primakoff-Bogolubov transformation. The spin Hamiltonian includes intralayer as well as interlayer nearest-neighbor exchange interactions, easy-plane anisotropy, and additionally a weak in-plane easy-axis anisotropy. The bilayer systems consist of two ferromagnetic (in-plane magnetization) monolayers that are coupled either ferromagnetically or antiferromagnetically. In the latter case, we analyze the spin-wave spectra in all magnetic phases, i.e., in the antiferromagnetic, spin-flop, and ferromagnetic ones.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Krzyżewska2024,
title = {Bilinear magnetoresistance in 2DEG with isotropic cubic Rashba spin–orbit interaction},
author = {Anna Krzyżewska and Anna Dyrdał},
url = {https://www.sciencedirect.com/science/article/pii/S0304885323012659?via%3Dihub},
doi = {10.1016/j.jmmm.2023.171615},
year = {2024},
date = {2024-01-01},
journal = {Journal of Magnetism and Magnetic Materials},
volume = {589},
pages = {171615},
abstract = {Bilinear magnetoresistance has been studied theoretically in 2D systems with isotropic cubic form of Rashba spin–orbit interaction. We have derived the effective spin–orbital field due to current-induced spin polarization and discussed its contribution to the unidirectional system response. The analyzed model can be applied to the semiconductor quantum wells as well as 2DEG at the surfaces and interfaces of perovskite oxides.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Jafari2024,
title = {Effect of strain on the electronic and magnetic properties of bilayer T-phase VS2 : A first-principles study},
author = {Mirali Jafari and Anna Dyrdał},
url = {https://www.sciencedirect.com/science/article/pii/S0304885323012684?via%3Dihub},
doi = {10.1016/j.jmmm.2023.171618},
year = {2024},
date = {2024-01-01},
journal = {Journal of Magnetism and Magnetic Materials},
volume = {589},
pages = {171618},
abstract = {Using the Density Functional Theory (DFT) calculations, we determined the electronic and magnetic properties of a T-phase VS2
bilayer as a function of tensile and compressive strain. First, we determine the ground state structural parameters and then the band structure, magnetic anisotropy, exchange parameters, and Curie temperature. Variation of these parameters with the strain is carefully analyzed and described. The easy-plane anisotropy, which is rather small in the absence of strain, becomes remarkably enhanced by tensile strain and reduced almost to zero by compressive strain. We also show that the exchange parameters and the Curie temperature are remarkably reduced for the compressive strains below roughly −4%.

},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Zarezad2024,
title = {Skyrmion-deriven topological spin and charge Hall effects in diffusive antiferromagnetic thin films},
author = {Amir Zarezad and Józef Barnaś and Anna Dyrdał and Alireza Qaiumzadeh},
url = {https://www.sciencedirect.com/science/article/pii/S0304885323012490?via%3Dihub},
doi = {10.1016/j.jmmm.2023.171599},
year = {2024},
date = {2024-01-01},
journal = {Journal of Magnetism and Magnetic Materials},
volume = {589},
pages = { 171599},
abstract = {We investigate topological Hall effects in a metallic antiferromagnetic (AFM) thin film and/or at the interface of an AFM insulator–normal metal bilayer with a single skyrmion in the diffusive regime. To determine the spin- and charge Hall currents, we employed a Boltzmann kinetic equation with both spin-dependent and spin-flip scatterings. The interaction between conduction electrons and static skyrmions is included in the Boltzmann equation via the corresponding emergent magnetic field arising from the skyrmion texture. We compute intrinsic and extrinsic contributions to the topological spin Hall effect and spin accumulation, induced by an AFM skyrmion. We show that although the spin Hall current vanishes rapidly outside the skyrmion, the spin accumulation can be finite at the edges far from the skyrmion, provided the spin diffusion length is longer than the skyrmion radius. In addition, We show that in the presence of a spin-dependent relaxation time, the topological charge Hall effect is finite and we determine the corresponding Hall voltage. Our results may help to explore antiferromagnetic skyrmions by electrical means in real materials.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Wang2022b,
title = {Skyrmion lattice hosted in synthetic antiferromagnets and helix modes},
author = {X.-G. Wang and L. Chotorlishvili and G. Tatara and Anna Dyrdał and Guang-hua Guo and V. K. Dugaev and Józef Barnaś and S.S.P. Parkin and A. Ernst},
url = {https://journals.aps.org/prb/abstract/10.1103/PhysRevB.106.104424},
doi = {10.1103/PhysRevB.106.104424},
year = {2022},
date = {2022-09-20},
journal = {Phys. Rev. B},
volume = {106},
pages = {104424},
abstract = {Thin ferromagnetic films can possess unconventional magnetic properties, opening a new road for using them in spintronic technologies. In the present work exploiting three different methods, we comprehensively analyze phason excitations of a skyrmion lattice in synthetic antiferromagnets. To analyze phason excitations of the skyrmion lattice, we have constructed an analytical model based on three coupled helices and found a linear gapless mode. Micromagnetic simulations also support this result. Moreover, a similar result has been achieved within the rigid skyrmion lattice model based on the coupled Thiele's equations, when the coupling between skyrmions in different layers of the synthetic antiferromagnetic is comparable to or larger than the intralayer coupling. In addition, we also consider the orbital angular momentum and spin pumping current associated with phason excitations. Due to the gapless excitations in the case of skyrmion lattice, the pumping current is nonzero for the arbitrary frequency of pumping microwaves. In the case of individual skyrmions, no current is pumped when microwave frequency is inside the gap of the spectrum of individual skyrmions.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Wang2022,
title = {Skyrmion Echo in a System of Interacting Skyrmions},
author = {X.-G. Wang and Guang-hua Guo and Anna Dyrdał and Józef Barnaś and V. K. Dugaev and S. S. P. Parkin and A. Ernst and L. Chotorlishvili},
url = {https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.129.126101},
doi = {10.1103/PhysRevLett.129.126101},
year = {2022},
date = {2022-09-14},
journal = {Phys. Rev. Lett.},
volume = {129},
pages = {126101},
abstract = {We consider helical rotation of skyrmions confined in the potentials formed by nanodisks. Based on numerical and analytical calculations we propose the skyrmion echo phenomenon. The physical mechanism of the skyrmion echo formation is also proposed. Because of the distortion of the lattice, impurities, or pinning effect, confined skyrmions experience slightly different local fields, which leads to dephasing of the initial signal. The interaction between skyrmions also can contribute to the dephasing process. However, switching the magnetization direction in the nanodiscs (e.g., by spin transfer torque) also switches the helical rotation of the skyrmions from clockwise to anticlockwise (or vice versa), and this restores the initial signal (which is the essence of skyrmion echo).},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Chotorlishvili2022,
title = {Rectification of the spin Seebeck current in noncollinear antiferromagnets},
author = {L. Chotorlishvili and Xi-guang Wang and Anna Dyrdał and Guang-hua Guo and Vitalii K. Dugaev and Józef Barnaś and J. Berakdar},
url = {https://journals.aps.org/prb/abstract/10.1103/PhysRevB.106.014417},
doi = {10.1103/PhysRevB.106.014417},
issn = {2469-9969},
year = {2022},
date = {2022-07-25},
journal = {Phys. Rev. B},
volume = {106},
number = {1},
pages = {014417},
abstract = {In the absence of an external magnetic field and a spin-polarized charge current, an antiferromagnetic system supports two degenerate magnon modes. An applied thermal bias activates the magnetic dynamics, leading to a magnon flow from the hot to the cold edge (magnonic spin Seebeck current). Both degenerate bands contribute to the magnon current but the orientations of the magnetic moments underlying the magnons are opposite in different bands. Therefore, while the magnon current is nonzero, the net spin current is zero. To obtain a nonzero net spin current, one needs to apply either a magnetic field or a spin-polarized charge current that lifts the bands' degeneracy. Here, attaching a thermal contact to one edge of a helical nanowire, we study three different magnonic spin currents: (i) the exchange, and (ii) Dzyaloshinskii–Moriya spin currents flowing along the helical nanowire, and (iii) magnonic spin current pumped into the adjacent normal-metal layer. We find that the combination of Dzyaloshinskii–Moriya interaction and external magnetic field substantially enhances the spin current compared to the current generated solely through a magnetic field. Due to nonreciprocal magnons and magnon dichroism effect, the Dzyaloshinskii–Moriya and exchange spin currents show left-right propagation asymmetry, with 20% of current rectification. The spin pumping current shows a slight asymmetry only in the case of a strong Dzyaloshinskii–Moriya interaction. The observed effects are explained in terms of the magnon dispersion relations and the magnon Doppler effect.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Jafari2022b,
title = {Electronic and magnetic properties of silicene monolayer under bi-axial mechanical strain: First principles study},
author = {Mir Ali Jafari and A. A. Kordbacheh and Anna Dyrdał},
url = {https://www.sciencedirect.com/science/article/pii/S0304885322002116?via%3Dihub},
doi = {10.1016/j.jmmm.2022.169260},
issn = {0304-8853},
year = {2022},
date = {2022-07-15},
journal = {J. Magn. Magn. Mater.},
volume = {554},
pages = {169260},
abstract = {Mechanical control of electronic and magnetic properties of 2D Van-der-Waals heterostructures gives new possibilities for further development of spintronics and information-related technologies. Using the density functional theory, we investigate the structural, electronic and magnetic properties of silicene monolayer with substituted Chromium atoms and under a small biaxial strain (-6% < e < 8%). Our results indicate that the Cr-doped silicene nanosheets without strain have magnetic metallic, half-metallic or semiconducting properties depending on the type of substitution. We also show that the magnetic moments associated with the monomer and vertical dimer substitutions change very weakly with strain. However, the magnetic moment associated with the horizontal dimer substitution decreases when either compressive or tensile strain is applied to the system. Additionally, we show that the largest semiconductor band-gap is approximately 0.13 eV under zero strain for the vertical Cr-doped silicene. Finally, biaxial compressive strain leads to irregular changes in the magnetic moment for Cr vertical dimer substitution.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Zarezad2022,
title = {Bilinear magnetoresistance in topological insulators: Role of magnetic disorder},
author = {Amir Nasser Zarezad and Anna Dyrdał},
url = {https://www.sciencedirect.com/science/article/pii/S0304885322001329?via%3Dihub},
doi = {10.1016/j.jmmm.2022.169167},
issn = {0304-8853},
year = {2022},
date = {2022-06-15},
journal = {J. Magn. Magn. Mater.},
volume = {552},
pages = {169167},
abstract = {Bilinear magnetoresistance is a nonlinear transport phenomenon that scales linearly with the electric and magnetic fields, and appears in nonmagnetic systems with strong spin–orbit coupling, such as topological insulators (TIs). Using the semiclassical Boltzmann theory and generalized relaxation time approximation, we consider in detail the bilinear magnetoresistance in an effective model describing surface states of three-dimensional topological insulators. We show that the presence of magnetic impurities remarkably modifies the BMR signal. In general, scattering on magnetic impurities reduces magnitude of BMR. Apart from this, an additional modulation of the angular dependence of BMR appears when the spin-dependent component of the impurity potential dominates the scalar one.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Jafari2022c,
title = {First Principle Study on Electronic and Transport Properties of Finite-Length Nanoribbons and Nanodiscs for Selected Two-Dimensional Materials},
author = {Mir Ali Jafari and Anna Dyrdał},
url = {https://www.mdpi.com/1420-3049/27/7/2228},
doi = {10.3390/molecules27072228},
issn = {1420-3049},
year = {2022},
date = {2022-03-29},
journal = {Molecules},
volume = {27},
number = {7},
pages = {2228},
abstract = {Using the density functional theory, we calculate electronic states of various nanoribbons and nanodiscs formed from selected two-dimensional materials, such as graphene, silicene, and hexagonal boron nitride. The main objective of the analysis is a search for zero-energy states in such systems, which is an important issue as their presence indicates certain topological properties associated with chirality. The analysis is also supported by calculating transport properties.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Jafari2022,
title = {Spin valve effect in two-dimensional VSe2 system},
author = {Mir Ali Jafari and Małgorzata Wawrzyniak-Adamczewska and Stefan Stagraczyński and Anna Dyrdał and Józef Barnaś},
url = {https://www.sciencedirect.com/science/article/pii/S0304885321011215?via%3Dihub},
doi = {10.1016/j.jmmm.2021.168921},
issn = {0304-8853},
year = {2022},
date = {2022-03-15},
journal = {J. Magn. Magn. Mater.},
volume = {548},
pages = {168921},
abstract = {Vanadium based dichalcogenides, VSe2, are two-dimensional materials in which magnetic Vanadium atoms are arranged in a hexagonal lattice and are coupled ferromagnetically within the plane. However, adjacent atomic planes are coupled antiferromagnetically. This provides new and interesting opportunities for application in spintronics and data storage and processing technologies. A spin valve magnetoresistance may be achieved when magnetic moments of both atomic planes are driven to parallel alignment by an external magnetic field. The resistance change associated with the transition from antiparallel to parallel configuration is qualitatively similar to that observed in artificially layered metallic magnetic structures. Detailed electronic structure of VSe2 was obtained from DFT calculations. Then, the ballistic spin-valve magnetoresistance was determined within the Landauer formalism. In addition, we also analyze thermal and thermoelectric properties. Both phases of VSe2, denoted as H and T, are considered.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Boboshko2022,
title = {Bilinear magnetoresistance in topological insulators: The role of spin–orbit scattering on impurities},
author = {Kateryna Boboshko and Anna Dyrdał and Józef Barnaś},
url = {https://www.sciencedirect.com/science/article/pii/S0304885321009318},
doi = {10.1016/j.jmmm.2021.168698},
year = {2022},
date = {2022-03-01},
journal = {Journal of Magnetism and Magnetic Materials},
volume = {545},
pages = {168698},
abstract = {Bilinear magnetoresistance (BMR) is a new kind of magnetoresistance, that scales linearly with electric and magnetic fields. This magnetoresistance occurs in systems with strong spin–orbit interaction. Additionally, this interaction also leads to quadratic magnetoresistance (QMR). We consider theoretically BMR and QMR in surface states of 3D topological insulators, and propose a new mechanism that leads to these effects. This mechanism is based on scattering on spin–orbit impurities. Accordingly, we assume the minimal model of surface electronic states in a single independent surface of a TI, and calculate both BMR and QMR induced as an interplay of current-induced spin polarization (or equivalently effective spin–orbit field) and spin–orbit scattering on impurities. We present detailed characteristics of both BMR and QMR, and compare our results with those obtained for TIs with spin-momentum locking inhomogeneities and hexagonal warping of the Dirac cones.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{physicaE_2021.114961,
title = {Non-equilibrium spin polarization in magnetic two-dimensional electron gas with k-linear and k-cubed Dresselhaus spin–orbit interaction},
author = {Anna Krzyżewska and Anna Dyrdał},
url = {https://doi.org/10.1016/j.physe.2021.114961},
doi = {10.1016/j.physe.2021.114961},
issn = {1386-9477},
year = {2022},
date = {2022-01-01},
journal = {Physica E},
volume = {135},
pages = {114961},
publisher = {North-Holland},
abstract = {The current-induced spin polarization (CISP) of charge carriers is one of the main mechanisms of spin-to-charge interconversion effects that can be used in new spintronics devices. Here, CISP is studied theoreticallyin symmetric quantum wells growing in [001] crystallographic direction, where both𝑘-linear and𝑘-cubedDresselhaus spin–orbit interactions are present. The exchange interaction responsible for perpendicular to planenet magnetization is also taken into account. The main focus is on the influence of cubic Dresselhaus termon CISP and the interplay between spin–orbit interaction (SOI) and the exchange field. The analytical andnumerical results are derived within the linear response theory and Matsubara Green’s function formalism.Apart from detailed numerical results, we also provide some analytical expressions that may be usefulfor interpretation of experimental results and for characterization of quantum wells with Dresselhaus SOI.Analytical expressions for the relevant Berry curvature are also derived, and it is shown that the Berrycurvature in magnetic 2DEG with cubic Dresselhaus interaction oscillates in the𝑘-space, while its averagedvalue is reduced. We also analyze the temperature behavior of CISP and calculate the low-temperature spinpolarizability due to heat current.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Inglot2021,
title = {Graphene with Rashba spin-orbit interaction and coupling to a magnetic layer: Electron states localized at the domain wall},
author = {Michał Inglot and Vitalii K. Dugaev and Anna Dyrdał and Józef Barnaś},
url = {https://journals.aps.org/prb/abstract/10.1103/PhysRevB.104.214408},
doi = {10.1103/PhysRevB.104.214408},
issn = {2469-9969},
year = {2021},
date = {2021-12-06},
journal = {Phys. Rev. B},
volume = {104},
number = {21},
pages = {214408},
abstract = {Electron states localized at a magnetic domain wall in a graphene with Rashba spin-orbit interaction and coupled to a magnetic layer are studied theoretically. It is shown that two one-dimensional bands of edge modes propagating along the domain wall emerge in the energy gap for each Dirac point, and the modes associated with different Dirac points K and K′ are the same. The coefficients describing decay of the corresponding wave functions with distance from the domain wall contain generally real and imaginary terms. Numerical results on the local spin density and on the total spin expected in the edge states characterized by the wave number ky are presented and discussed. The Chern number for a single magnetic domain on graphene indicates that the system is in the quantum anomalous Hall phase, with two chiral modes at the edges. In turn, the number of modes localized at the domain wall is determined by the difference in Chern numbers on both sides of the wall. These numbers are equal to 2 and −2, respectively, so there are four modes localized at the domain wall.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}