陈剑豪
北京大学物理学院量子材料科学中心
地点：唐楼A213
时间：2016-01-08 10:00
陈剑豪为北京大学物理学院量子材料科学中心研究员、博士生导师。2004 年毕业于浙江大学竺可桢学院，获理学学士。2009 年获美国马里兰大学（University of Maryland at College Park）物理学博士。2009 年至2012 年先后在美国马里兰大学和加州大学伯克利分校（University of California at Berkeley）从事博士后研究。2012 年入选国家青年千人计划。2013 年起在北京大学物理学院任教。主要研究方向为低维电子材料及纳米器件的物理与应用，原子尺度上的材料物性调控，以及超高真空条件下的原位输运表征。发表论文包括三篇Nature Physics，一篇Nature Nanotechnology，三篇Physical Review Letters 等，SCI 总引用次数超过3600 次。
In first half of this talk, I will briefly summarize the literature of in-situ quantum transport for 2D materials and our effort in developing special instruments for in-situ transport measurement. In the second half of this talk, I will discuss our recent conventional transport experiment on ultra-thin WTe2 field effect transistors as tunable magnetoresistance (MR) devices. We found that for ultra-thin WTe2 samples that are far away from charge neutrality, the MR of the samples can still be explained by the two-fluid model. By tuning the 2D electron-hole imbalance from 8.2 × 1017m-2 to 3.3 × 1017m-2, we were able to change the MR of the devices by 900%. The change of MR could be as large as 2.2 × 106 % if we could restore mobility of device to the mobility of its bulks crystals.Our result shows the potential of ultra-thin WTe2 in the applications such as magnetic field sensors, read heads in high density hard disks, random access memories, and galvanic isolators.