报告题目:Electric Field Control of Many-Body States in 2D Materials
报 告 人:Prof. Antonio H. Castro Neto
时 间:2016年1月4日(周一) 下午16:00
地 点:卢嘉锡楼报告厅(202)
Abstract
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教授简介:
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。
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能源材料化学协同创新中心
2016年1月1日