CAREER: Quantum Phases and Dynamics in Strongly Interacting, Non-Equilibrium Systems

University Of California-Berkeley, Berkeley CA

Investigators

Abstract

Non-technical Abstract: In equilibrium, the classification of different phases of matter is extremely well-studied. This has led to a deep understanding of the physics that distinguishes between, for example, superconductors and magnets, while also informing why the former is essential for biomedical magnetic resonance imaging (MRI) and the latter used in electrical transformers. These insights are typically rooted in the assumption of thermal equilibrium. When equilibration fails, so does much of our understanding. This CAREER award supports basic research into utilizing quantum mechanical building blocks --- composed of atoms, ions, molecules and photons --- to explore new phases of matter that can emerge in strongly-interacting systems which are out-of-equilibrium. To this end, the PI will explore two complementary directions. The first direction focuses on quantum mechanical systems where strong disorder prevents equilibrium from ever being reached. A key question in this context is whether one can realize novel, intrinsically out-of-equilibrium phases of matter. The second direction focuses on understanding the way in which quantum systems that do equilibrate, manage to do so. A particular question of interest is whether there exists a "speed limit" on equilibration and if so, whether experimental AMO systems with long-range interactions can reach this limit. Alongside these research goals, the PI will implement a multi-layered outreach program aimed at training, recruiting and retaining high school, undergraduate, and graduate students in the physical sciences. A particular focus will be the establishment of a research immersion initiative and summer internship program aimed at helping undergraduate students from two-year colleges gain hands-on research experience. The project also includes funding for a tailored mentorship program focused on teaching undergraduate and graduate students effective skills for science communication, enabling them to become advocates for science literacy in society. Technical Abstract: The last decade has seen the atomic, molecular and optical physics community make remarkable progress in the controlled manipulation of individual quanta. These advances have opened the door for the bottom-up realization of quantum many-body systems as well as the development of novel quantum technologies. This CAREER award supports basic research focused on utilizing the quantum optics toolbox associated with cold-atomic gases to explore topological phases, thermalization, and quantum dynamics in non-equilibrium systems. The non-equilibrium dynamics of entanglement and correlations remain some of the most poorly understood facets of quantum mechanics. To this end, the PI will explore new "universality classes" of quantum phases and dynamics, using a combination of analytic theoretical tools, state-of-the-art numerical computations, and experiments. In particular, the PI will characterize symmetry breaking and topological orders in strongly-interacting, periodically-driven, Floquet systems. While such periodic driving has emerged as a versatile tool in the quantum engineering of modern atomic systems, it remains an open question what specific types of novel phases can be realized in such Floquet systems. In addition, the PI will investigate foundational issues associated with the local quantum control of many-body systems. The proposed study will focus on leveraging tools from atomic and magnetic resonance spectroscopy, such as quantum phase estimation and quantum non-demolition measurement, to manipulate many-body excitations in disordered out-of-equilibrium systems. These research directions will also help to strengthen interdisciplinary connections between AMO physicists and condensed matter / quantum information scientists, as well as to provide a bridging dialogue between theoretical concepts and experimental implementations.