Quantum geometry and nonlinear Hall effects in topological materials
Abstract
Quantum materials exhibit novel electrical and optical properties that originate from the quantum nature of electron wavefunctions in solids. The study of quantum materials not only advances condensed matter theory, but also opens exciting opportunities for inventing new quantum technologies. In recent years, exciting progress has been made in understanding the quantum geometry of electron wavefunctions in relation to observable material properties. The rich and intricate quantum geometric structure of Bloch electrons gives rise to a variety of novel quantum phenomena. An example is the nonlinear Hall effect recently observed in two-dimensional and bulk materials, even at room temperature. The nonlinear Hall effect due to quantum geometry paves the way for innovative applications in high-frequency low-power electronics, offering an entirely new operational principle that surpasses the limitations of traditional semiconductor junctions. This breakthrough manifests in the form of high-efficiency rectifiers capable of functioning at terahertz frequencies, even under zero bias voltage and with extremely low input power. Consequently, the quest for quantum materials exhibiting large intrinsic transport nonlinearity is of paramount importance, as they provide a new ground for exploring unprecedented quantum phenomena and developing cutting-edge technologies. Based on our long-term synergistic collaboration, our proposal presents a methodical and integrative strategy for advancing quantum geometric theory of electromagnetic responses, and identifying novel materials that exhibit pronounced quantum geometric effects and promise breakthrough in quantum rectification and quantum sensing. By combining quantum geometric theory and first-principles calculations, this proposal will significantly advance our fundamental understanding of quantum materials while also paving the way for practical applications.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 05, 2025
- Source ID
- FA23862414043
Entities
People
- Liang Fu
Organizations
- Air Force Office of Scientific Research
- Massachusetts Institute of Technology
- United States Air Force