报告题目 (Title)：Novel electronic states in two-dimensional bismuth materials（二维铋材料中的新奇量子物态）

报告人 (Speaker)：苟健 研究员 （浙江大学物理学院）

报告时间 (Time)：2024年5月28日（周二）14:00

报告地点 (Place)：校本部 D123

邀请人 (Inviter)：孙硕 副教授

主办部门：理学院物理系

报告摘要：

Bismuth (Bi) is known for its unique electronic properties, owing to its distinctive position in the periodic table of elements. In this talk, I will discuss three types of two-dimensional (2D) Bi materials studied through molecular beam epitaxial (MBE) and low-temperature scanning probe microscopy (STM/qPlus-AFM). Firstly, we found, due to the large spin-orbital coupling (Soc) and close electronegativity between Bi and Sn, the introduction of Sn in Sn2Bi produce a giant Rashba splitting and asymmetric electron-hole band structure at the Fermi surface[1]. Secondly, the anisotropic structure of black phosphorous-like Bi (BP-Bi) monolayer enables the creation of a single-layer honeycomb Bi (bismuthene) with various twist moiré superlattices, in which the modulation of topological edge states has been observed[2]. finally, take the advantage of high resolution of qPlus-AFM measurement, we discovered that weak sp orbital hybridization of Bi facilitates electron transfer between sublattices and in-plane polarization switching in elementary BP-Bi monolayer[3]. This observation confirms the emergence of novel single-element ferroelectric states in the realm of solid-state physics.