Non-Gaussian feature of the output field from a double qubit-cavity ultrastrong coupling system  

作　　者：Sheng-wen Xu Shi-yu Dai Teng Zhao 

机构地区：[1]Center for Quantum Science and Technology,Jiangxi Normal University,Nanchang 330022,China

出　　处：《Communications in Theoretical Physics》2024年第7期30-36,共7页理论物理通讯（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant No.12104195);the Natural Science Foundation of Jiangxi Province of China(Grant No.20232BAB211033).

摘　　要：We investigate the non-Gaussian feature of radiation in a circuit quantum electrodynamics(QED)system where two qubits are strongly coupled to a single-mode cavity.In the regime of ultrastrong coupling(USC),the rotating-wave approximation is not valid,and the Rabi Hamiltonian contains counter-rotating wave terms,leading to level crossing and avoided crossings in the energy spectrum.We further analyze the intensity-amplitude correlation of the output field in these two novel scenarios.In the USC regime,the creation and annihilation operators in the correlation function are replaced,allowing for the identification of non-Gaussian features in the output field.Our findings reveal that despite the absence of squeezing effects in the output light,significant non-Gaussian characteristics are present.Additionally,we demonstrate that as the driving or coupling strength increases,the non-Gaussian features of the output field become more pronounced.This suggests that USC systems hold broad potential applications in the realms of nonlinear optics and the generation of non-Gaussian states.

关 键 词：ultrastrong coupling NON-GAUSSIAN intensity-amplitude correlation 

分 类 号：O413.2[理学—理论物理]