CAREER: Equilibrium and Dynamics of Strongly Interacting Many-body Systems

California Institute Of Technology, Pasadena CA

Investigators

Abstract

NONTECHNICAL SUMMARY The Division of Materials Research and the Division of Physics contribute funds to this CAREER award, which supports an integrated research and educational effort on theoretical quantum many-body physics. Quantum many-body physics studies the behavior of quantum mechanical systems that contain a large number of constituents. Due to both the quantum mechanical nature of the systems and the large number of constituents, exotic physical properties can emerge that usually do not have a direct analog in classical systems. Of particular interest, and the focus of this project, are strongly correlated systems where the components of the system interact strongly with each other, taking the system into a completely different regime than those encountered in non-interacting or weakly interacting systems. This project aims to study the theoretical foundations of new features in these systems that are made possible due to the strong interactions, both at equilibrium and in dynamical processes. By constructing new theoretical models and by designing experimentally feasible ways to probe the predicted properties, the project aims to not only deepen our understanding of strongly correlated phenomena in condensed matter physics, but to also contribute to their study and application in quantum information theory, quantum field theory, and cold-atom experiments. Moreover, as part of the educational component of the project, the PI aims to integrate novel concepts of quantum mechanics and quantum many-body physics into outreach and educational activities by developing a new course on "Many-body Entanglement and Topological Phases" for senior undergraduate and graduate students, and by organizing a "quantum chess" tournament for local high-school students, a large proportion of which are from underrepresented groups. The goal of the tournament is to introduce the basic concepts of quantum mechanics to high-school students through engaging games. TECHNICAL SUMMARY The Division of Materials Research and the Division of Physics contribute funds to this CAREER award, which supports an integrated research and educational effort on theoretical quantum many-body physics. The goal of the project is to advance the fundamental understanding of quantum many-body systems, both at equilibrium and in dynamical processes. The research focuses on systems with strong interactions, and explores novel topological phenomena and many-body dynamics, which cannot exist in non-interacting systems. The PI will rely on her previous research on exactly solvable lattice models, and on field-theory analysis and tensor-network numerical approaches to tackle these problems. In particular, this project will focus on the following topics: i) Constructing and analyzing new discrete gauge theories in 3D, ii) Interpreting and generalizing the topological order in 3D fractal quantum codes using a coupled-layer construction, with concomitant potential quantum-information applications, iii) Mapping the Lieb-Robinson light cone in diffusive and many-body localized systems with experimentally feasible measurement schemes. The PI will explore the non-perturbative regime of strongly interacting quantum many-body systems, and will look for fundamentally new universal behavior. Potential achievements include: i) discovering new twisted-gauge theories in 3D and understanding of their properties both in the bulk and on the surface; ii) finding a generalized topological phase diagram which connects the fractal quantum code to more conventional topological orders, and constructing more physical models that can serve as quantum memories; (3) understanding the ability of various correlator measures in detecting information propagation in diffusive or many-body localized systems, and finding experimentally feasible setups for realizing such measurements. Moreover, as part of the educational component of the project, the PI aims to integrate novel concepts of quantum mechanics and quantum many-body physics into outreach and educational activities by developing a new course on "Many-body Entanglement and Topological Phases" for senior undergraduate and graduate students, and by organizing a "quantum chess" tournament for local high-school students, a large proportion of which are from underrepresented groups. The goal of the tournament is to introduce the basic concepts of quantum mechanics to high-school students through engaging games.