CAREER: Quantum Gases in Low-Dimensional Rings

Dartmouth College, Hanover NH

Investigators

Abstract

General audience abstract: Many advanced technologies rely on special properties of quantum materials like superconductors, where currents can flow without resistance. The activities supported by this award will improve our understanding of these important materials, especially how their behavior changes when they are formed into very thin wires. The experiments will involve microscopic clouds of a few thousand lithium atoms shaped into circuit-like configurations by laser light. Near absolute zero temperature the atoms in these "quantum gases" can be used to simulate the behavior of electrons in solid materials, and the project will examine how fluctuations, magnetization, and the shape of the circuit affect its properties. The results will shed light on the processes that give these materials their special properties, improving our ability to use them and to discover new kinds of quantum materials. Solving these types of problems requires mastery of important critical thinking and quantitative reasoning skills that are often not adequately or systematically included in the physics curriculum. The integrated educational component of this project is to draw on real-world laboratory experiences to develop interactive training exercises focused on these skills, which can be used to improve the effectiveness of teaching in advanced physics lab courses. The goal is to ensure that every physics student is systematically trained in "how to think like a physicist" before they graduate. Technical audience abstract: This award supports a research program investigating quantum phenomena and quantum phases of matter in in quasi-one-dimensional fermionic systems with cyclic boundary conditions. The approach will be to confine lithium-6 atoms to precisely controlled ring-shaped optical dipole traps, taking advantage of a unique combination of tunable interactions, dimensionality, and boundary conditions to achieve experimental goals that include characterizing spontaneous symmetry breaking in the Gaudin-Yang model, measuring transport in Luttinger liquids, and determining whether polarized superfluid phases can exist in this setting. The experiments will also establish methods for creating ring lattices with ultracold atoms, enabling studies of even more unusual quantum phases including some with topological order. These experiments will provide important tests of 1D theories in a configuration that are often considered but have been very difficult to realize in laboratory materials. The results will also support broad efforts to generalize successful 1D theories to higher dimensions, which will eventually improve our ability to predict the existence of quantum phases of matter and understand their properties. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.