Irreversible photon transfer in an ensemble of $\Lambda$-type atoms and photon diode

TL;DR

This paper demonstrates how a Lambda-type atomic ensemble can facilitate irreversible photon transfer between cavity modes, enabling the design of a photon diode that directs single photons from multiple inputs to a single output.

Contribution

It introduces a novel analogy between Lambda-type atomic ensembles and bosonic reservoirs, enabling engineered irreversible photon transfer and the realization of a photon diode device.

Findings

Observation of quantum Zeno and anti-Zeno effects.

Control over decay channels via reservoir engineering.

Implementation of a photon diode for single-photon routing.

Abstract

We show that a pair of quantized cavity modes interacting with a spectrally broadened ensemble of Lambda-type atoms is analogous to an ensemble of two level systems coupled to a bosonic reservoir. This provides the possibility for an irreversible photon transfer between photon modes. The density of states as well as the quantum state of the reservoir can be engineered allowing the observation of effects such as the quantum Zeno- and anti-Zeno effect, the destructive interference of decay channels and the decay in a squeezed vacuum. As a particular application we discuss a photon diode, i.e. a device which directs a single photon from anyone of two input ports to a common output port.