Manipulating quantum materials with quantum light

TL;DR

This paper demonstrates how coupling strongly correlated electron systems to a cavity mode can alter their magnetic and electronic properties, leading to new phases and interactions, with potential implications for quantum material control.

Contribution

It introduces a method to manipulate quantum materials using quantum light, specifically showing cavity-induced modifications in the Fermi-Hubbard model's properties.

Findings

Cavity coupling enhances magnetic interactions in the ground state.

It induces a long-range electron-electron interaction at less than half filling.

A new phase with momentum-space pairing is observed due to cavity effects.

Abstract

We show that the macroscopic magnetic and electronic properties of strongly correlated electron systems can be manipulated by coupling them to a cavity mode. As a paradigmatic example we consider the Fermi-Hubbard model and find that the electron-cavity coupling enhances the magnetic interaction between the electron spins in the ground-state manifold. At half filling this effect can be observed by a change in the magnetic susceptibility. At less than half filling, the cavity introduces a next-nearest neighbour hopping and mediates a long-range electron-electron interaction between distant sites. We study the ground state properties with Tensor Network methods and find that the cavity coupling can induce a new phase characterized by a momentum-space pairing effect for electrons.