Quantum super-cavity with atomic mirrors

TL;DR

This paper explores how atomic systems embedded in coupled microcavities can act as tunable quantum mirrors and form a supercavity, enabling control over single-photon transport and creating quantum analogs of classical optical devices.

Contribution

It introduces the concept of a quantum supercavity formed by atomic mirrors in a cavity array, demonstrating tunable photon confinement and reflection properties.

Findings

Single two-level systems can fully reflect single photons.

Two two-level systems can create quasi-bound states for photons.

The properties of the supercavity are tunable via atomic frequencies.

Abstract

We study single-photon transport in an array of coupled microcavities where two two-level atomic systems are embedded in two separate cavities of the array. We find that a single-photon can be totally reflected by a single two-level system. However, two separate two-level systems can also create, between them, single-photon quasi-bound states. Therefore, a single two-level system in the cavity array can act as a mirror while a different type of cavity can be formed by using two two-level systems, acting as tunable "mirrors", inside two separate cavities in the array. In analogy with superlattices in solid state, we call this new "cavity inside a coupled-cavity array" a super-cavity. This supercavity is the quantum analog of Fabry-Perot interferometers. Moreover, we show that the physical properties of this quantum super-cavity can be adjusted by changing the frequencies of these two-level systems.