Sensing coherent phonons with two-photon interference

Abstract

Detecting coherent phonons pose different challenges compared to coherent photons due to the much stronger interaction between phonons and matter. This is especially true for high frequency heat carrying phonons, which are intrinsic lattice vibrations experiencing many decoherence events with the environment, and are thus generally assumed to be incoherent. Two photon interference techniques, especially coherent population trapping (CPT) and electromagnetically induced transparency (EIT), have led to extremely sensitive detection, spectroscopy and metrology. Here, we propose the use of two photon interference in a three-level system to sense coherent phonons. Unlike prior works which have treated phonon coupling as damping, we account for coherent phonon coupling using a full quantum-mechanical treatment. We observe strong asymmetry in absorption spectrum in CPT and negative dispersion in EIT susceptibility in the presence of coherent phonon coupling which cannot be accounted for if only pure phonon damping is considered. Our proposal has application in sensing heat carrying coherent phonons effects and understanding coherent bosonic multi-pathway interference effects in three coupled oscillator systems.

Phonon coherence and its effect on thermal conductivity of nanostructures

“…Note: Adapted from Ref. [186]. and quantum theory of coherence and the optical theory of classical and quantum coherence in heat transport.…”

“…proposed the use of two-photon interference such as coherent population trapping (CPT) or electromagnetic induced transparency (EIT) to detect phonon coherence [186].…”

“…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].…”

“…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].…”

Transforming heat transfer with thermal metamaterials and devices

“…A direct detection of phonon coherence can provide more information. Recently, the use of two-photon interference such as coherent population trapping (CPT) or electromagnetic induced transparency (EIT) to detect phonon coherence was proposed 98 .…”