Physicists at Caltech have reached a significant milestone in quantum research by verifying long-standing predictions of conformal field theory. For decades, these mathematical frameworks described how systems behave during phase transitions, yet direct experimental proof remained elusive. The team, led by Manuel Endres and Jason Alicea, used a quantum simulator to map the energy levels of synthetic quantum matter.
To perform this test, researchers used optical tweezers to trap strontium atoms in a precise line. By exciting these atoms into high-energy Rydberg states, they created a system that acted as a single, cohesive entity. The team then placed this chain at a critical tipping point between two states. Using a technique called many-body modulation spectroscopy, they vibrated the system at specific frequencies to identify the energy rungs predicted by theory.
The results matched the theoretical predictions for the Ising and tricritical Ising models with high accuracy. Researchers measured energy levels in chains of up to 35 atoms, observing that the spectra aligned with universal curves. This experiment marks the first time these specific energy ratios have been observed in a controlled environment.
This work demonstrates how tools built for quantum computing now serve as powerful instruments for fundamental physics. Because the platform allows for individual atom control, the team could isolate hidden symmetry excitations and manipulate chain ends to verify different theoretical predictions. Future research will shift from one-dimensional lines to two-dimensional grids, where conformal field theories remain less understood.
The study involved collaborations with Université Paris-Saclay and the Technical University of Munich. Funding for this project came from multiple government and private sources, including the Department of Energy and the National Science Foundation.