Overlaying optical lattices for simulation of complex frustrated antiferromagnets

TL;DR

This paper introduces a method to create specialized optical lattices for simulating complex frustrated antiferromagnetic spin systems in two dimensions, enabling exploration of quantum phases and transitions.

Contribution

It presents a novel optical lattice design technique that uses a single laser frequency to simulate frustrated spin models with adjustable interaction ratios.

Findings

Broad parameter space for simulating $J_1$-$J_2$ models

Detection of quantum phases via polarization spectroscopy

Feasible setup for studying frustrated spin systems

Abstract

We present design techniques of special optical lattices that allow quantum simulation of spin frustration in two-dimensional systems. By carefully overlaying optical lattices with different periods and orientations, we are able to adjust the ratio between the nearest-neighbor and next-nearest-neighbor interaction strengths in a square spin lattice and realize frustration effects. We show that only laser beams of a single frequency is required, and the parameter space reachable in our design is broad enough to study the important phases in the $J_1$-$J_2$ frustrated Heisenberg model and checkerboard antiferromagnet model. By using the polarization spectroscopy for detection, distinct quantum phases and quantum phase transition points can be characterized straightforwardly. Our design thus offers a suitable setup for simulation of frustrated spin systems.