Electron liquids and crystals in nonreciprocal and topological quantum systems

About This Grant

NONTECHNICAL SUMMARY This award supports theoretical research on charge and heat transport in quantum electronic systems, focusing on novel two-dimensional materials, nanostructures, and superconducting devices. The research addresses both fundamental and applied physics, with potential to bring innovations for quantum technologies. The analytical methods developed in this work will be applicable to a wide range of problems in the quantum physics of low-dimensional systems. Modern technology relies on electronic devices that perform a variety of functions, such as transistors, diodes, and other key components. The central theme of this project is to investigate nonreciprocal transport phenomena. Nonreciprocity in quantum materials refers to the phenomenon where a system’s response to an external stimulus (such as electric current, magnetic field, or light) depends on the direction of the applied stimulus. In other words, the system’s transport or optical properties are asymmetric when the direction of the current or field is reversed, violating conventional reciprocity relations. One of the main goals of this project is to study the superconducting diode effect in materials and junctions, which could lead to new functionalities, since superconductors can support dissipationless currents. Another focus of the research is exploring nonreciprocal thermoelectric effects, where heat can be converted into electricity and vice versa. The research program is closely integrated with education and outreach efforts. These initiatives include training undergraduate and graduate students and mentoring postdoctoral scholars in advanced topics in quantum physics. To inspire the next generation of physicists, the project will also engage students through science Olympiads and summer schools, providing valuable experience and exposure to modern developments in the field. TECHNICAL SUMMARY This project focuses on theoretical research in electron quantum transport and nonreciprocity in correlated systems and devices. The research agenda addresses both the fundamental physics of electronic correlations in complex materials and the practical physics of mesoscopic devices, particularly in the context of quantum science and superconducting nanostructures. The proposed scientific program is partly motivated by recent and ongoing experiments and will be conducted in close collaboration with several research groups. These collaborations are a key pillar of the project’s success. The work is structured around three main thrusts, each comprising interconnected sub-projects: [1] Transport Phenomena in Correlated Electron Systems. This thrust aims to develop a new kinetic theory that accurately accounts for correlations between electron scattering and long-range disorder potentials. These potentials may manifest as scalar or pseudo-vector fields, particularly relevant to multi-valley conductors with spatially varying strain. Applications include transport in topological moiré systems and nonlinear phenomena such as magnetochiral anisotropy and second harmonic generation. [2] Noncentrosymmetric Superconducting Systems. This line of research investigates the microscopic mechanisms underlying the superconducting diode effect, explores spin-galvanic effects, and studies interferometry in multiterminal Josephson junctions. It also aims to uncover transport anomalies at the interface between quantum Hall systems and superconductors. [3] Correlated Electronic Multilayers. This thrust explores electronic crystal phases in two-dimensional materials and investigates anomalous and nonreciprocal Coulomb drag phenomena in 1D and 2D devices, as well as the behavior of odd electron liquids. The project strongly emphasizes training graduate and undergraduate students by integrating them into research within a highly collaborative environment alongside postdoctoral scholars and colleagues from other groups. Additionally, the outreach and engagement component of the program targets a broad audience, including the general public, middle and high school students, and professional physics majors. Key components of this program include: Science Olympiad (preparing and mentoring students for science competitions); Podium Speaker Series (hosting talks to inspire and engage students in STEM fields); Quantum Summer Schools (organizing local summer schools to support students from Midwestern states and coordinating the advanced Boulder Summer School); Scientific Coordination of Events (organizing conferences and workshops to foster scientific collaboration). 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.