Cavity-induced quantum spin liquids

TL;DR

This paper proposes a novel method to induce and stabilize quantum spin liquid states by coupling quantum magnets to optical cavities, creating tunable long-range interactions that promote frustration even in unfrustrated systems.

Contribution

It introduces a cavity-based approach to engineer frustration and stabilize spin liquids in quantum magnets, expanding the possibilities for quantum state control.

Findings

Cavity coupling induces long-range interactions between spins.

Spin liquid states are stabilized over a broad parameter range.

Unfrustrated systems can host spin liquids via cavity-induced frustration.

Abstract

Quantum spin liquids provide paradigmatic examples of highly entangled quantum states of matter. Frustration is the key mechanism to favor spin liquids over more conventional magnetically ordered states. Here we propose to engineer frustration by exploiting the coupling of quantum magnets to the quantized light of an optical cavity. The interplay between the quantum fluctuations of the electro-magnetic field and the strongly correlated electrons results in a tunable long-range interaction between localized spins. This cavity-induced frustration robustly stabilizes spin liquid states, which occupy an extensive region in the phase diagram spanned by the range and strength of the tailored interaction. Remarkably, this occurs even in originally unfrustrated systems, as we showcase for the Heisenberg model on the square lattice.