报告题目：Quantum Materials Based on Epitaxial Moirè Superlattices

报 告 人：王学森 副教授（新加坡国立大学物理系）

报告时间：2023年4月21日（周五）上午10:00

报告地点：物理科学与技术学院新楼5楼多功能厅

报告摘要：

In recent years, the moirè superlattices formed with twisted homo- or hetero-bilayer of graphene or TMDCs have been investigated intensively. Such moiré bilayers provide us with a class of designed nanomaterials that possess novel electronic properties, including flat energy bands and heavy fermions. These moiré structures can exhibit metal-insulator transition, superconductivity and topological insulators. The moiré structures constructed from the exfoliated atomic layers, however, have certain limitations that severely hinder their further development and applications in nano-electronics and photonics. To expand the family of such electronic systems, we are investigating the moirè superlattices formed with atomic overlayers epitaxially grown on suitable crystalline substrates. To realize the epitaxial moirè structures, the atomic layer and the substrate should have a lateral period mismatch of about 5-10%; the interfacial binding strength should be in the van der Waals range; then the electronic states of the overlayer are perturbed with a moderate moiré periodic potential. Such epitaxial moiré systems offer certain advantages over those twisted bilayers made of exfoliated layers in terms of accessible material and electronic parameter ranges, sample quality and practical device mass production. Possible candidates of such epitaxial moiré system we have explored include Group-VA (P, As, Sb and Bi) atomic layers on Group IV-VI or other bulk crystals. The exploration can be extended to a much broad range of overlayers and substrates. The possibility of tuning the interfacial coupling strength will be demonstrated and discussed.

报告人简介：

王学森副教授，目前就职于新加坡国立大学物理系，1982年毕业于复旦大学物理系获学士学位，1990年获美国马里兰大学物理系博士学位。先后在美国加州大学圣巴巴拉分校，美国明尼苏达大学，美国马里兰大学，香港科技大学工作；2001年6月至今在新加坡国立大学物理系工作。主要研究领域包括表面科学、薄膜、纳米科学。他在扫描隧道显微镜、表面科学、纳米科学等领域有着丰富研究经历。已在Phys. Rev. Lett.，Phys. Rev. B，Appl. Phys. Lett.，Nanotechnology等国际学术期刊发表SSCI/SCI论文98篇，TOP期刊收录39篇，论文引用总次数1376次，其中他引次数1032次。

邀 请 人：张晨栋 教授