Quantum Zeno switch for single-photon coherent transport

TL;DR

This paper introduces a quantum Zeno switch that uses high-frequency modulation of a two-level system to control single-photon transport in a waveguide, enabling on/off switching of photon reflection.

Contribution

It presents a novel method to control TLS-environment coupling via dynamical quantum Zeno effect, with analytical and numerical validation for single-photon transport control.

Findings

Coupling can be turned on or off by adjusting modulation parameters.

Photon reflection vanishes at zeros of a Bessel function.

Analytical results agree with Floquet numerical simulations.

Abstract

Using a dynamical quantum Zeno effect, we propose a general approach to control the coupling between a two-level system (TLS) and its surroundings, by modulating the energy level spacing of the TLS with a high frequency signal. We show that the TLS--surroundings interaction can be turned on or off when the ratio between the amplitude and the frequency of the modulating field is adjusted to be a zero of a Bessel function. The quantum Zeno effect of the TLS can also be observed by the vanishing of the photon reflection at these zeros. Based on these results, we propose a quantum switch to control the transport of a single photon in a 1D waveguide. Our analytical results agree well with numerical results using Floquet theory.