Multiple quantum exceptional, diabolical, and hybrid points in multimode bosonic systems
Prof. Jan Peřina, Palacky University and and Institute of Physics CAS, Olomouc, Czech Republic

Date, Time
21.11, 15:00 - 15:30

Location
hybrid meetnig (room 16), link (MSTeams) >>>

The existence and degeneracies of quantum exceptional, diabolical, and hybrid (i.e., diabolically degenerated exceptional) points of simple bosonic systems composed of up to six modes with damping and amplification are analyzed. Their dynamics governed by quadratic non-Hermitian Hamiltonians, involving unidirectional mode coupling, is followed using the Heisenberg-Langevin equations. Conditions for the observation of inherited quantum hybrid points with up to sixth-order exceptional and second-order diabolical degeneracies are revealed. Exceptional and diabolical points and their degeneracies observed in the dynamics of higher-order field-operator moments are analyzed in their full complexity. Interestingly, the analysis of a system with non-conventional dynamics exhibiting an inherited quantum exceptional point only in a sub-space of the whole Liouville space is presented.

[1] J. Peřina Jr., A. Miranowicz, G. Chimczak, A. Kowalewska‑Kudłaszyk: Quantum Liouvillian exceptional and diabolical points for bosonic fields with quadratic Hamiltonians: The Heisenberg-Langevin equation approach, Quantum 6, 883 (2022).