CAREER: Dynamics and Transport of Excited Strongly Correlated Many-Particle Systems

Cuny College Of Staten Island, Staten Island NY

Investigators

Abstract

TECHNICAL SUMMARY This CAREER award supports computational and theoretical research, and education aimed at elucidating the emergence of macroscopic dissipative transport from inherently deterministic and usually quantum microscopic motion of interacting particles. Recent explorations of this fundamental question have been anchored by three phenomena: (i) the so called "bad metal" behavior in synthetic conductors, (ii) many-body localization, and (iii) equilibration of anharmonic oscillators in one dimension. While the first of these is well documented in many interesting materials, such as vanadium dioxide, Buckminsterfullerene, and high temperature superconductors, the latter two are primarily motivated by fundamental questions of many-body theory. The PI aims to propose clear ways to discern these often subtle phenomena in simple experiments. Rather than more common approaches that involve taking a limit of zero absolute temperature, the PI will focus on finite temperature approaches for which very precise numerical computations of dynamical properties are possible. Because phenomena of interest dominate asymptotic low frequency response at non-zero temperatures, calculation at finite temperature enables a convenient avenue for exploration. By most common approaches are not able to address hallmarks of correlated transport as violation of Mott-Ioffe-Regel limit and non-Drude optical response. Motivated by the particularly spectacular examples of correlated transport extending from low to very high temperatures, the PI will explore the idea that the high temperature regime may serve as the novel starting point for analyzing a broad range of experiments done at intermediate to low temperature, from bad metals to heavy fermions to apparent quantum critical points. This award supports educational opportunities for graduate and undergraduate students. The PI plans a diverse research group where students at different levels will be involved in mentoring, education and research experiences. The PI plans to teach an exploration-based course in cross-disciplinary computational research. The PI aims to help boost a public appreciation of materials research with a focus on exposing non-expert audiences to cutting edge research in an accessible form with the aim of effectively stimulating lifelong interest in learning. Outreach activities stemming from this CAREER award will also include colloquium-style public lectures about condensed matter physics and PI's own research. NONTECHNICAL SUMMARY This CAREER award supports computational and theoretical research, and education involving novel phenomena associated with electron motion in synthetic materials that conduct electricity, magnetic materials, and atomic motion in gases of atoms cooled near the absolute zero of temperature. The PI will develop theoretical and numerical methods to describe the motion of electrons in response to applied fields, for example an applied voltage. The PI seeks in part to understand the microscopic origins of dissipation that degrades electron motion. The PI takes a different approach than much of the previous research that has been done on this topic. The research more generally focuses on understanding the dynamical behavior of many electron or many atom systems in which the constituent electrons or atoms interact with each other, the systems are described by quantum mechanics, but the temperature may be high enough that the system is approaching the crossover to classical mechanics. Many electron systems such as these may appear in certain kinds of materials and in nanostructures under the right conditions. This award supports fundamental research that aims at our understanding of electronic properties of materials and the microscopic origins of how energy is lost in electronic motion. The results may lead to the discovery of new phenomena advancing fundamental science and may also lead to new technological applications. This award supports educational opportunities for graduate and undergraduate students. The PI plans a diverse research group where students at different levels will be involved in mentoring, education and research experiences. The PI plans to teach an exploration-based course in cross-disciplinary computational research. The PI aims to help boost a public appreciation of materials research with a focus on exposing non-expert audiences to cutting edge research in an accessible form with the aim of effectively stimulating lifelong interest in learning. Outreach activities stemming from this CAREER award will also include colloquium-style public lectures about condensed matter physics and PI?s own research.