Physics Colloquium: “Decagonal Quasicrystals With Ultracold Atoms”

The Syracuse University Department of Physics is pleased to welcome Charles Brown, Assistant Professor of Physics at Yale University, for his talk titled, “Decagonal Quasicrystals with Ultracold Atoms.”

Charles Brown started as an Assistant Professor of Physics at Yale in 2023. He has expertise in the generation and measurement of gaseous and liquid quantum matter. He leads an experimental group at Yale that focuses on trapping ultracold atoms in optical lattices to explore how geometry and topology affect emergent properties in exotic quantum materials. Charles is also a member of the ALPHA collaboration, whose goal is to search for axion dark matter. He was awarded the Air Force Office of Scientific Research Young Investigator Award and an NSF CAREER award for his work exploring the physics of quantum quasicrystals.

Abstract: Quasicrystals are aperiodic with long-range order, exhibiting an absence of translation symmetry and featuring rotational symmetries that are mathematically forbidden in periodic lattices. In 1984, Shechtman performed X-ray diffraction measurements on a metallic alloy, revealing 10-fold rotational symmetry in the diffraction pattern. This work eventually led to the redefinition of what constitutes a crystal, and the recognition of the reality of aperiodic crystals. Shechtman was then awarded the 2011 Nobel prize in chemistry for the discovery of aperiodic crystals. In recent decades, band structure and its interplay with topology has provided deep insight into intriguing behavior in periodic crystalline quantum materials. However, thirty years after the discovery of aperiodic crystals, the role of the energy spectrum and its interplay with topology is not well-understood for quasicrystals because standard theoretical methods used to study the energy spectrum of a crystal rely on translational symmetry. Quantum simulation of a quasicrystal would open a window into quasicrystalline “band structure” and topology that is difficult to access with theoretical and analytical methods alone. This talk will describe the design of an experiment in which a quantum gas is confined within a 10-fold rotation-symmetric quasiperiodic optical lattice and will mention planned first measurements.