Dr. Penghao Zhu
Center for Emergent Materials, Department of Physics, The Ohio State University
Chirality and Non-Hermitian Skin Effect
Faculty Host: n/a
Abstract: The wave phenomena of systems with gain and loss can often be captured by a non-Hermitian (NH) Hamiltonian description. With appropriately chosen gain and loss, a NH system with open boundaries can exhibit an extensive number of exponentially localized states on the boundary; a phenomenon known as the NH skin effect (NHSE). Remarkably, the NHSE is a manifestation of intrinsically NH topology of the complex energy spectrum of NH Hamiltonians. Significantly, it has been shown that the NH topology, and thus the NHSE, is related to one of the most important and fundamental properties in modern physics – chirality. In this talk, I will first introduce the relationship among NHSE, topology, and chirality in 1D systems. Then, I will discuss the chirality in 3D, and its corresponding NHSE induced by external magnetic field and lattice defects. Next, I will talk about a generalized chirality in 2D crystalline systems, and illustrate the unconventional NH dynamics and NHSE associated to this generalized chirality. Finally, I will discuss open questions and future research.
Bio: Penghao Zhu earned his PhD degree from UIUC. His research primarily focused on various aspects of topological crystalline phases, such as entanglement, magnetism, geometric response, and the bulk-boundary correspondence, in both Hermitian and non-Hermitian systems.
Students and postdocs are invited to stay and chat with the speaker from 11:30-12:00.