Liouvillian exceptional points of any order in dissipative linear bosonic systems

In our study we explore exceptional points (EPs) of any higher order in dissipative linear bosonic systems based on the Liouvillian framework [1]. This framework, compared to the non-Hermitian Hamiltonians, can faithfully reveal the true quantum nature of EPs by taking into account quantum jumps. We show that the higher-order EPs of a Liouvillian can be identified by the coherence and spectral functions at the steady state. Moreover, the coherence functions can offer a convenient tool to probe extreme system sensitivity to external perturbations in the vicinity of such higher-order EPs [2].


[1] F. Minganti, A. Miranowicz, R. W. Chhajlany, F. Nori, Phys. Rev. A 100, 062131 (2019)
[2] I. Arkhipov, A. Miranowicz, F. Minganti, F. Nori, Phys. Rev. A 102, 033715 (2020)