### 学术报告：On-Demand Topological Matter via Light-Matter Interaction

发布时间：2017-12-12 南师物理学院 浏览次数：

报告题目：On-Demand Topological Matter via Light-Matter Interaction

**报告人:**

**龚江滨教授**

**新加坡国立大学物理系**

时间: 12月15日（星期五），下午15:00-16:00

地点： 行健楼437

邀请单位：南京师范大学物理科学与技术学院

**Abstract**

New topological phases of matter via light-matter interaction such as periodic time modulation, termed as Floquet topological phases, are now a topic of wide interest. I shall first briefly discuss a few examples to explain how and why periodic driving can generate intriguing topological phases, such as Bloch bands with high Chern numbers, topologically nontrivial flat bands, etc. I shall then focus on the transport signatures of Floquet topological matter. In particular, after highlighting the so-called Floquet sum rule, I shall show how light can be used to create multiple pairs of chiral Majorana modes in topological hybrid junctions, yielding robust half-quantized conductance plateaus at one-half and three-halves of the fundamental conductance quantum (fundamental charge squared divided by the Planck constant). Such half quantization quantum transport is both subtle and fascinating because it emerges only after a summation over contributions from all Floquet sidebands. This distinctive transport signature can thus serve as a hallmark of photoinduced Chiral Majorana fermion modes in topological heterojunctions.

**References:**

1. Photoinduced (1/2) e^2/h and (3/2)e^2/h conductance plateaus in topological insulator-superconductor heterostructures, arXiv:1711.09540, by H.H. Yap, L.W. Zhou, C.H. Lee, and J.B. Gong.

2. A computational study of two-terminal transport of Floquet quantum Hall insulators, PRB 96, 165443 (2017), by H.H. Yap, L.W. Zhou, J.S. Wang, and J.B. Gong.

3. Topological effects in chiral symmetric driven systems, PRB 90, 195419 (2014), by D.Y.H. Ho and J.B. Gong.

4. Generating many Majorana modes via periodic driving: A superconductor model, PRB 87, 201109 (R) (2013), by Q.J. Tong, J.H. An, J.B. Gong, H.G. Luo, and C.H. Oh.

5. Quantized adiabatic transport in momentum space, PRL 109, 010601 (2012) (Editor’s Suggestion), by D.Y.H. Ho and J.B. Gong.

**Biosketch of Prof. Gong Jiangbin**

Prof. Gong Jiangbin obtained his B. Sc from Nanjing University and his Ph.D from the University of Toronto. He joined the National University of Singapore (NUS) in 2006 after postdoctoral studies at the University of Toronto and the University of Chicago. Prof. Gong’s theoretical research interests include nonlinear dynamics and quantum chaos, quantum dynamics control, quantum thermodynamics, non-Hermitian quantum mechanics, and topological matter. Prof. Gong is appointed as Deputy Head (research) of the Department of Physics of NUS since July 2017. He recently won the NUS Faculty of Science Outstanding Scientist Award 2016, the prestigious Singapore National Research Foundation Investigatorship 2017, and the Institute of Physics Singapore World Scientific Medal 2017.