Researchers at Caltech have hit a major milestone in physics by experimentally confirming long-standing theoretical predictions about quantum matter. Using a neutral-atom quantum simulator, the team measured energy spectra predicted by two conformal field theories for the first time.
Physicists rely on universality to understand phase transitions. This concept suggests that different materials, such as boiling water or magnets losing their charge, follow the same mathematical rules when they transition between states. These rules are often described by conformal field theory. Until now, these theories existed primarily as mathematical models.
The team, led by Manuel Endres and Jason Alicea, trapped chains of up to 35 strontium atoms using optical tweezers. By applying a technique called many-body modulation spectroscopy, they gently shook the atom chain at specific frequencies to observe how the system responded. These responses mapped out energy levels that functioned like rungs on a ladder. The experiment proved these rungs match the exact ratios predicted by Ising and tricritical Ising models.
This setup leverages technology originally built for quantum computing. The ability to control individual atoms allows researchers to test theories that were previously out of reach. By adjusting the atoms at the ends of the chain, the team produced patterns that confirmed precise predictions of the tricritical Ising theory. This confirms that these theoretical models accurately describe physical reality at the quantum level.
Looking ahead, the researchers aim to expand these experiments into two-dimensional quantum systems. This next phase will allow them to probe regimes where current theoretical predictions are incomplete and where classical computers face limitations. This research provides a new way to map out fundamental physics without needing the answers in advance.