Single-photon transport in a whispering-gallery mode microresonator directionally coupled with a two-level quantum emitter

TL;DR

This paper explores single-photon transport in a whispering-gallery mode microresonator coupled with a two-level quantum emitter, demonstrating the equivalence of different analytical methods and extending to complex chiral systems.

Contribution

It introduces the transfer matrix method as an alternative approach and proves its equivalence with cavity QED and single-photon transport methods for QE-microresonator systems.

Findings

Transfer matrix method is equivalent to cavity QED and transport methods.

Parameter relations among the three methods are precisely deduced.

Extension to multi-resonator systems interacting with QEs in a chiral manner.

Abstract

We investigate the single-photon transport problem in the system of a Whispering-Gallery mode microresonator directionally coupled with a two-level quantum emitter (QE). This QE-microresonator coupling system can usually be studied by cavity quantum electrodynamics and the single-photon transport methods. However, we find that if we treat a two-level QE as a single-photon phase-amplitude modulator, we can also deal with such systems using the transfer matrix method. Further, in theory, we prove that these three methods are equivalent. The corresponding relations of respective parameters among these approaches are precisely deduced. Our work can be extended to a multiple-resonator system interacting with two-level QEs in a chiral way. Therefore, the transfer matrix method may provide a convenient and intuitive form for exploring more complex chiral QE-resonator interaction systems.