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Engineering random spin models with atoms in a high-finesse cavity
Nick Sauerwein1, Francesca Orsi1, Philipp Uhrich2,3
1Institute of Physics and Center for Quantum Science and Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
Nature Physics
|August 14, 2023
Summary
Researchers created a controllable disordered spin system using an atomic cloud in a cavity. This breakthrough allows for the physical realization of quantum many-body models, advancing quantum computing and condensed-matter physics.
Area of Science:
- Quantum physics
- Condensed-matter physics
- Quantum computing
Background:
- Disordered quantum many-body models with all-to-all interactions have broad applications but lack physical realization.
- These models are crucial in fields like spin glasses, holographic duality, and quantum annealing.
Purpose of the Study:
- To physically realize and study all-to-all interacting, disordered quantum spin systems.
- To explore the interplay between interactions and disorder in quantum systems.
- To enable the design of arbitrary spin Hamiltonians via programmable cavity-mediated interactions.
Main Methods:
- Utilized an atomic cloud within an optical cavity subjected to a controllable light shift.
- Tuned the system between disordered central-mode and Lipkin-Meshkov-Glick models by adjusting atom-cavity detuning.
- Employed spectroscopic probing of low-energy excitations to analyze the effects of disorder.
Main Results:
- Observed disorder breaking collective coupling in the central-mode model, leading to 'grey' states.
- Demonstrated the evolution of the Lipkin-Meshkov-Glick model from a ferromagnetic ground state to a paramagnetic phase with increasing disorder.
- Identified the emergence of semi-localized eigenstates in the disordered Lipkin-Meshkov-Glick regime.
Conclusions:
- Successfully realized a tunable, disordered all-to-all interacting spin system in a cavity.
- Provided experimental insights into the competition between interactions and disorder in quantum many-body systems.
- Paved the way for programmable quantum simulations and the design of novel quantum Hamiltonians.
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