Cavity-free Photon Blockade Induced by Many-body Bound States

TL;DR

This paper demonstrates theoretically that strong quantum nonlinear effects, including photon blockade and single photon generation, can occur in an open waveguide system coupled to a four-level quantum emitter, without the need for a cavity.

Contribution

It introduces a novel cavity-free photon blockade mechanism induced by many-body bound states in an open waveguide coupled to a four-level system.

Findings

Photon blockade achieved without cavities

Presence of many-body bound states mediates photon-photon correlations

Potential for sub-Poissonian single photon source

Abstract

The manipulation of individual, mobile quanta is a key goal of quantum communication; to achieve this, nonlinear phenomena in open systems can play a critical role. We show theoretically that a variety of strong quantum nonlinear phenomena occur in a completely open one-dimensional waveguide coupled to an N-type four-level system (4LS). We focus on photon blockade and the creation of single photon states in the absence of a cavity. Many-body bound states appear due to the strong photon-photon correlation mediated by the 4LS. These bound states cause photon blockade which can generate a sub-Poissonian single photon source.