In a recent article in Nature Communications, University of Iowa Prof. Yannick Meurice and colleagues reported the observation of a new quantum physics phase called the "floating phase," where the crystalline order is not “locked” to an underlying grid. The physical setup is a ladder-shaped array of Rubidium atoms proposed by Meurice as a quantum simulator to study the evolution of charged particles interacting with photons in the context of particle physics. The atoms are prepared in two states and can be interpreted as qubits. 

Scientists working at the quantum computing company QuEra associated with Misha Lukin group at Harvard used up to 92 neutral-atom qubits to observe the floating phase in agreement with theoretical work performed in the collaboration. By measuring the correlations among atoms and analyzing their periodicity, they saw patterns interpolating between crystalline phases which became continuous as they increased the size of their experiments, and which characterize the floating phase. 

The study of quantum phases and quantum phase transitions is one of the central topics in condensed matter, atomic, and, more recently for quantum simulators in high energy physics. This research contributes to the fundamental knowledge of quantum mechanics and phase transitions. It explores how quantum systems behave under different conditions, which is crucial for developing new theories and models.  By studying these phases, researchers can also improve the design and stability of quantum computers and could lead to advancements in various technologies, such as quantum sensors and communication systems. 

The paper “Probing quantum floating phases in Rydberg atom arrays” was published Jan. 16, 2025 in Nature Communications. First author is Jin Zhang, who was a postdoc at the University of Iowa who worked with Prof. Meurice at the beginning of the project and then moved to Chongqing University as an assistant professor. Collaborators for the study included Sergio Cantu, Fangli Liu and Sheng-Tao Wang at QuEra and Prof. Shan-Wen Tsai at the University of California, Riverside. The work was supported by a Department of Energy award, “Foundations of Quantum Computing for Gauge Theories and Quantum Gravity” (DE-SC0019139); Meurice is the principal investigator.