Tunable waveguide lattices with non-uniform parity-symmetric tunneling

TL;DR

This paper explores how varying the tunneling profile in a one-dimensional waveguide lattice affects quantum dynamics and correlations, revealing rich, tunable behaviors with potential applications in photonic systems.

Contribution

It introduces a model with a site-dependent tunneling function and demonstrates how its parameter controls wavepacket dynamics and quantum correlations.

Findings

Wavepacket spread varies with tunneling parameter .

Quantum correlations are highly sensitive to tunneling form.

Rich, tunable dynamics in waveguide arrays with position-dependent couplings.

Abstract

We investigate the single-particle time evolution and two-particle quantum correlations in a one-dimensional $N$-site lattice with a site-dependent nearest neighbor tunneling function $t_\alpha(k)=t_0[k(N-k)]^{\alpha/2}$. Since the bandwidth and the energy levels spacings for such a lattice both depend upon $\alpha$, we show that the observable properties of a wavepacket, such as its spread and the relative phases of its constitutents, vary dramatically as $\alpha$ is varied from positive to negative values. We also find that the quantum correlations are exquisitely sensitive to the form of the tunneling function. Our results suggest that arrays of waveguides with position-dependent evanascent couplings will show rich dynamics with no counterpart in present-day, traditional systems.