Colloquium – Shaozhi Li – Phonon Controlled Quantum Phenomena in Correlated Materials

Speaker: Shaozhi Li (Clemson University)

Title: Phonon Controlled Quantum Phenomena in Correlated Materials

Abstract: In quantum materials, millions of electrons and ions interact with each other, generating diverse quantum phenomena. Today, it remains a significant challenge in simulating such complex microscopic interactions. In this talk, I will discuss the great potential of AI techniques in solving many-body interactions and accelerating science discovery. A detailed example of an application in solving the electron-phonon coupling will be given [1]. After demonstrating the efficiency of AI techniques, I will discuss phonon-controlled macroscopic phenomena in correlated quantum materials. The first example is the interfacial electron-phonon interaction-induced topological superconductivity. I will explain that a forward phonon scattering supports superconductivity under a high magnetic field, which is opposite to the prediction of the BCS theory [2]. The second example is the phonon-controlled thermal Hall effect in the Kitaev quantum spin liquid 𝛼-RuCl₃. It was found that 𝛼-RuCl₃ exhibits a half-quantized thermal effect, which is attributed to the topological band of Majorana Fermions. I will demonstrate that this half-quantized thermal Hall effect can be controlled by phonons and explain the sample-dependent thermal Hall effect observed in experiments.

[1] Shaozhi Li, et al., Phys. Rev. B 100, 020302(R) (2019)

[2] Shaozhi Li, et al., Communications Physics 6. 235 (2023)

[3] Shaozhi Li and Satoshi Okamoto, Phys. Rev. B 106, 024413 (2022)

Host: Sergei Gleyzer