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 (浙江大学物永利)
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:永利物理系
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.