Multimode cavity QED Ising spin glass

Phys. Rev. Lett. (2025)
 
In this paper, researchers describe how they have created a new kind of quantum simulator that mimics the behavior of a spin glass — a complex magnetic system where particles interact in random, competing ways — using light and ultracold atoms inside an optical cavity.

The atoms, held in place by laser tweezers, act like tiny magnets (spins) that can all interact with one another through the light bouncing inside the cavity. The team could study systems of up to 25 spins and visualize their behavior using the light emitted from the cavity.

By carefully changing the conditions of the system, the researchers observed that the disorder and structure of the spin glass depend on how quickly the system is driven through a key transition. Surprisingly, even though the setup is not in thermal equilibrium, it shows the same hallmark behavior predicted in classic spin glass theory — such as replica symmetry breaking, a sign of deep internal organization. This new platform could be used to study how such systems store and recall information (like an associative memory) and to explore processes such as aging and rejuvenation in complex quantum materials.

The paper’s authors are Brendan Marsh, David Atri Schuller, Yunpeng Ji, Henry Hung, Giulia Socolof, Deven Bowman, Jonathan Keeling and Benjamin Lev, who conducted the work at Stanford University and the University of St. Andrews.