Observation of pair tunneling and coherent destruction of tunneling in arrays of optical waveguides

TL;DR

This paper experimentally demonstrates a photonic system simulating the one-dimensional two-particle Hubbard model, showing pair tunneling and coherent destruction of tunneling, advancing quantum simulation in photonics.

Contribution

It introduces a novel optical waveguide array setup that simulates strongly-interacting two-particle quantum systems with controllable parameters.

Findings

Observation of pair tunneling in optical waveguides

Demonstration of coherent destruction of tunneling (CDT)

Control over interaction strength and driving force

Abstract

We report on the experimental realization of a photonic system that simulates the one-dimensional two-particle Hubbard model. This analogy is realized by means of two-dimensional arrays of coupled optical waveguides, fabricated using femtosecond laser inscription. By tuning the analogous "interaction strength", we reach the strongly-interacting regime of the Hubbard Hamiltonian, and demonstrate the suppression of standard tunneling for individual "particles". In this regime, the formation of bound states is identified through the direct observation of pair tunneling. We then demonstrate the coherent destruction of tunneling (CDT) for the paired particles in the presence of an engineered oscillating force of high frequency. The precise control over the analogous "interaction strength" and driving force offered by our experimental system opens an exciting route towards quantum simulation of few-body physics in photonics.