Caltech Team Uses Quantum Simulator to Probe Universal Rules of Quantum Matter

Insider Brief

• Caltech researchers used a neutral-atom quantum simulator to directly measure energy spectra predicted by two conformal field theories for the first time, experimentally confirming decades-old theoretical predictions.
• The team trapped chains of up to 35 strontium atoms with optical tweezers and used many-body modulation spectroscopy to measure energy levels associated with the Ising and tricritical Ising models.
• Researchers plan to extend the technique to larger, two-dimensional quantum systems, including regimes where theoretical predictions are incomplete and classical computers may be unable to calculate the results.
• Image: This AI image shows a chain of strontium atoms (orange), each held in an optical tweezer (blue cones). The chain sits within a modulated laser field. The evenly spaced lines above represent the ladder of excitation energies predicted by conformal field theory, whose rungs the team measured. (Stephan Naus)

PRESS RELEASE — When different materials transition from one phase to another, such a water coming to a boil or a magnet losing its ability to attract metals, something remarkable can happen: They begin to behave identically, following the same mathematical rules. “Physicists call this trait universality—the messy, microscopic details wash out and only a few essential features survive,” explains Jason Alicea, William K. Davis Professor of Theoretical Physics. The math underlying these universal traits is commonly described by a theoretical framework called conformal field theory.