Dissipation-free approach for realizing non-Hermitian dynamics in a superconducting circuit  

作　　者：Yi-Hao Kang Yang Xiao Yu Wang Qi-Ping Su Chui-Ping Yang 

机构地区：[1]School of Physics,Hangzhou Normal University,Hangzhou,311121,China [2]Fujian Key Laboratory of Quantum Information and Quantum Optics,Fuzhou University,Fuzhou,350108,China [3]Department of Physics,Fuzhou University,Fuzhou,350108,China

出　　处：《Science China(Physics,Mechanics & Astronomy)》2025年第3期74-91,共18页中国科学:物理学、力学、天文学(英文版)

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.11374083,11774076,and U21A20436);the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0301705)。

摘　　要：Non-Hermitian dynamics exhibits a wealth of surprising and potentially useful phenomena.However,it is typically realized by coupling a system with thermal reservoirs,which makes the system suffer from thermal fluctuations associated with the dissipation.Here,we propose a dissipation-free approach to realize non-Hermitian dynamics using a superconducting circuit composed of two resonators and a superconducting qutrit.The non-Hermiticity arises in the dynamical matrix for the evolution of the two resonators in the Heisenberg picture,via a photon-number non-conserved dynamics.The energy spectrum of the non-Hermitian dynamical matrix can be retrieved by measuring the state of the two resonators,and a phase transition of the energy spectrum can be observed by varying the control parameters.In the realization of the non-Hermitian dynamics,the dissipation of the system and the post-selection are not required.Thus,the approach is implemented in a deterministic way,and the reservoir-induced noise is suppressed.Numerical simulations indicate that the energy spectrum of the non-Hermitian dynamical matrix obtained via the measurement of the resonators is in accordance with the theoretical prediction.Moreover,we demonstrate the parity discrimination for the state of two four-level qudits as an application,exhibiting the potential of the non-Hermitian dynamics in the field of quantum measurement.This work opens a new avenue for the realization of non-Hermitian dynamics and may have a significant implication in exploring the non-Hermitian phenomena.

关 键 词：non-Hermitian dynamics superconducting circuit non-Hermitian phase transition 

分 类 号：O413[理学—理论物理]