Understanding photon sideband statistics and correlation for determining phonon coherence

Phonon coherence and its effect on thermal conductivity of nanostructures

“…Here, the relationship between the detector and the signal is no longer a simple function like that of the photoelectric detector. Ding et al derived the second-order correlation for optical sideband detection and proposed an interference experiment in Figure 15(a) which allows one to measure phonon coherence just like photons [187]. Figure 15(b) shows examples of the second-order correlation at zero delay for different phonon numbers.…”

“…There has been various work on generating and detecting coherent heat-carrying phonons in materials, especially at low temperatures [75][76][77][78][79][80][81][82][83], and it would be interesting to apply the concept of coherence in these experiments. Recently, work by Ding et al further implemented concepts in quantum coherence in potentially characterizing phonon coherence [186,187]. In one work, Ding et al proposed the use of two-photon interference such as coherent population trapping (CPT) or electromagnetic induced transparency (EIT) to detect phonon coherence [186].…”

“…However, such a response may not be applicable for phonon detectors, and Equation (2) may not be valid for detecting phonon coherence. Ding et al considered a popular phonon detector [187] called optical sideband detection [77,190,191]. Here, the relationship between the detector and the signal is no longer a simple function like that of the photoelectric detector.…”