报告题目：Quantum transport in topological insulators
摘要：
Three-dimensional (3D) topological insulators (TI) are a novel class of electronic materials with topologically-nontrivial band structure such that the bulk is gapped and insulating yet the surface has topologically protected gapless conducting states. Such “topological surface states” (TSS) give helically spin polarized Dirac fermions, and offer a promising platform to realize various other novel physics such as topological magnetoelectric effects and Majorana fermions, and may enable technological applications in areas such as spintronics and thermoelectrics. However, it is often challenging to unambiguously access and study the transport properties of TSS in many practical TI materials due to non-negligible bulk conducting states. I will discuss some of our experiments on high-quality “intrinsic” TIs with insulating bulk and surface-dominated conduction that allow us to reveal a number of characteristic quantum transport properties of spin-helical Dirac fermion topological surface states, such as the “half-integer” quantum Hall effect [1-2] and “half-integer” Aharonov-Bohm effect [3]. I will also discuss some issues and cautions related to interpreting commonly measured magnetotransport signatures such as “2D” quantum oscillations, weak antilocalization and linear magnetoresistance that may or may not arise from topological surface states or be unique to topological insulators [4-6]. If time permits, I may discuss other ways of probing TI transport using magnetic (spin-dependent) or superconducting (phase sensitive) electrodes.
References:
[1] Y. Xu et al., Nature Physics 10, 956 (2014)
[2] Y. Xu et al., Nature Communications 7, 11434 (2016)
[3] L. A. Jauregui et al., Nature Nanotechnology 11, 345 (2016)
[4] H. Cao et al., Physical Review Letters 108, 216803 (2012)
[5] L. A. Jauregui et al., Scientific Reports 5, 8452 (2015)
[6] J. Tian et al., Scientific Reports 4, 4859 (2014)
简 历：
西安交通大学应用数学系，本科，1996毕业。
MIT，数学系硕士，导师Jacob White，1999。
普林斯顿,电子工程系，导师Daniel C. Tsui ，2005。
2005-2007，Rice大学博士后。
2007年受聘普渡大学电子与计算机工程助理教授，并于2012年获tenure副教授，2016年任教授。
研究领域：
Experimental condensed matter physics & nanoscience (graphene/2D materials, topological insulators,2D electrons/quantum Hall physics) and cold atom/quantum physics/quantum photonics (Bose-Einsteincondensation, cold molecules, hybrid quantum systems)
获奖情况：
Masao Horiba Award for nanoparticle Measurement (2015);
Purdue University Faculty Scholar (2013-2018);
Purdue University Excellence in Research Award (2012, 2013);
NSF CAREER Award (2009-2014);
IBM Faculty Award (2009);
Defense Threat Reduction Agency (DTRA) Young InvestigatorAward (2009-2011);
Miller Family Professorship, Purdue University (2007-2012);
J. Evans Attwell-Welch Postdoctoral Fellowship in Nanoscience, Rice University (2005-2007); International Union ofPure and Applied Physics (IUPAP)