Spectral characterization of non-Gaussian quantum noise: Keldysh approach and application to photon shot noise
Yuxin Wang, Aashish A. Clerk · Physical Review Research · 2020
This work provides a universal characterization of nonclassical, non-Gaussian environmental fluctuations in the frequency domain, based on the Keldysh approach to quantum noise characterization. The authors also present a calculation of frequency-resolved third cumulant, i.e., quantum bispectrum, of a nontrivial quantum bath. They show that the quantum bispectrum reveals that quantum fluctuations can break detailed balance.