Realizing the $XY$ Hamiltonian in polariton simulators

TL;DR

This paper demonstrates that polariton graphs can be used as an efficient platform to simulate the $XY$ Hamiltonian, enabling the study of various magnetic phases and phase transitions in complex systems.

Contribution

It introduces a novel approach to simulate the $XY$ Hamiltonian using polariton condensate lattices with customizable geometries.

Findings

Successfully realized ferromagnetic, anti-ferromagnetic, and frustrated spin configurations.

Simulated various lattice geometries including square, triangular, linear, and disordered graphs.

Provided a new route to study complex phenomena like superfluids and spin-liquids.

Abstract

Several platforms are currently being explored for simulating physical systems whose complexity increases faster than polynomially with the number of particles or degrees of freedom in the system. Defects and vacancies in semiconductors or dielectric materials, magnetic impurities embedded in solid helium \cite{lemeshko13}, atoms in optical lattices, photons, trapped ions and superconducting q-bits are among the candidates for predicting the behaviour of spin glasses, spin-liquids, and classical magnetism among other phenomena with practical technological applications. Here we investigate the potential of polariton graphs as an efficient simulator for finding the global minimum of the $XY$ Hamiltonian. By imprinting polariton condensate lattices of bespoke geometries we show that we can simulate a large variety of systems undergoing the U(1) symmetry breaking transitions. We realise various magnetic phases, such as ferromagnetic, anti-ferromagnetic, and frustrated spin configurations on unit cells of various lattices: square, triangular, linear and a disordered graph. Our results provide a route to study unconventional superfluids, spin-liquids, Berezinskii-Kosterlitz-Thouless phase transition, classical magnetism among the many systems that are described by the $XY$ Hamiltonian.