Phases of a Two-Dimensional Rydberg Atom Array

March 31, 2020
figure 1 from the article: Phase diagram of the 2D Rydberg Hamiltonian

The ability to fully control coherent quantum many-body systems is an exciting and rapidly developing frontier. Besides quantum information processing, controlled many-body systems can enable new insights into strongly correlated phases of matter. On this front, arrays of neutral atoms trapped in optical tweezers and interacting via controlled excitations into atomic Rydberg states provide an especially promising platform. In fact, their particular properties have allowed for the programmable realization and high-fidelity manipulation of a wide range of effective interacting spin models

In a recent paper,* researchers from the groups of Profs. Subir Sachdev and Mikhail Lukin at Harvard unveiled the zero-temperature phase diagram of a two-dimensional square-lattice array of such neutral atoms, excited into Rydberg states and interacting via strong van der Waals interactions. This system was shown to host a rich variety of phases featuring complex density-wave orderings, ranging from intricate classical packings to intrinsically quantum-ordered phases stabilized by quantum fluctuations. Accompanying these phases are a host of novel quantum phase transitions. The work thus highlights Rydberg quantum simulators in higher dimensions as promising platforms to realize exotic many-body phenomena.

*Rhine Samajdar, Wen Wei Ho, Hannes Pichler, Mikhail D. Lukin, and Subir Sachdev, "Complex Density Wave Orders and Quantum Phase Transitions in a Model of Square-Lattice Rydberg Atom Arrays," Phys. Rev. Lett. 124, 103601 (2020) DOI: