Coherent destruction of tunneling in a lattice array under selective in-phase modulations

TL;DR

This paper investigates the phenomenon of coherent destruction of tunneling (CDT) in a lattice array with selective in-phase modulations, demonstrating how tuning parameters can decouple driven and undriven sites and enable controlled light transport.

Contribution

It introduces a scheme for CDT in selectively modulated lattice systems, including high-order couplings, and proposes applications in optical waveguide arrays for light control.

Findings

CDT occurs when $J_0(A/\omega)=0$, decoupling driven and undriven sites.

CDT can be achieved even with high-order non-nearest couplings.

A scheme for directed single-particle transport using CDT is proposed.

Abstract

We explore the coherent destruction of tunneling (CDT) in a lattice array under selective in-phase harmonic modulations, in which some selected lattice sites are driven by in-phase harmonic oscillating fields and other lattice sites are undriven. Due to the occurrence of CDT, if the driving amplitude $A$ and the driving frequency $\omega$ are tuned to satisfy the zeroth-order Bessel function $J_0(A/\omega)=0$, the driven lattice sites are approximately decoupled with the undriven lattice sites. The CDT even takes place in lattice systems with high-order couplings between non-nearest lattice sites. By using the CDT, we propose a scheme for realizing directed transport of a single particle. It is possible to observe the CDT in the engineered optical waveguide array, which provides a new opportunity for controlling light propagation and designing switch-like couplers.