题  目：Electric Field Control of Many-Body States in 2D Materials

讲座人: Prof. Antonio H. Castro Neto

时  间：2016年1月4日（周一) 下午16:00

地  点：厦门大学卢嘉锡楼二楼报告厅（202）

To understand the complex physics of a system with strong electron–electron interactions, the ideal is to control and monitor its properties while tuning an external electric field applied to the system (the electric-field effect). Indeed, complete electric field control of many-body states in strongly correlated electron systems is fundamental to the next generation of condensed matter research and devices. Octahedral titanium diselenide (1T-TiSe₂) is a prototypical twodimensional material that reveals a charge-density wave (CDW) and superconductivity in its phase diagram, presenting several similarities with other layered systems such as copper oxides, iron pnictides, and crystals of rare-earth elements and actinide atoms. By studying 1T-TiSe₂ single crystals with thicknesses of 10 nanometres or less, encapsulated in two-dimensional layers of hexagonal boron nitride, we achieve unprecedented control over the CDW transition temperature (tuned from 170 kelvin to 40 kelvin), and over the superconductivity transition temperature (tuned from a quantum critical point at 0 kelvin up to 3 kelvin). Electrically driving TiSe₂ over different ordered electronic phases allows us to study the details of the phase transitions between many-body states. Our results show that spatially modulated electronic states are fundamental to the appearance of two-dimensional superconductivity.

Antonio H. Castro Neto教授的简历：

自2001年起在美国波士顿大学（Boston University）物理系任正教授，现为新加坡国立大学石墨烯研究中心主任、物理系杰出教授，主要从事石墨烯及其他二维原子晶体、超导体、强关联体系、无序磁系统等的理论研究，取得了一系列高水平的开创性研究成果，先后在Science、Nature、Nature子刊上发表论文8篇，在PRL上发表论文48篇，其论文被SCI引用15000余次，h因子为52。Neto教授在国际学术界特别是近年来在石墨烯研究领域十分活跃，任欧洲物理快报（EPL）副主编，作为国际会议组织者和分会主席主持多次重要国际会议，应邀在国际会议上作特邀报告100多次。