:::

1092-專題演講-1100303-游至仕(台師大物理系)

演講活動
張貼人:李明芳公告日期:2021-02-01
  

Time1100303 (Wed.) 14:20~16:20

SpeakerProf. 游至仕(YOU, Jhih-Shih)

國立臺灣師範大學物理學系/Department of Physics, National Taiwan Normal University

TitleNew Hall effect goes nonlinear

AbstractIn this talk I will introduce our recent study of the nonlinear Hall effect in materials with time-reversal symmetry. In the absence of magnetic field, the Hall effect in the linear response regime vanishes due to time-reversal symmetry. However, a transverse charge current can still occur in second-order response to an external electric field, as a result of the Berry curvature dipole (BCD) in momentum space. Candidate 2D materials to observe this effect are two-dimensional transition-metal dichalcogenides (TMDCs). The application of strain and electrical displacement field can systematically control the BCD in TMDCs. We also demonstrate that 3D giant-Rashba material bismuth tellurium iodine (BiTeI) exhibits a pressure-driven phase transition between topological and trivial insulators, which is accompanied by a giant enhancement of the BCD which can be probed in transport and optoelectronic experiments. While there has been much effort to understand nonlinear transport due to a BCD in bulk, we further find that the topological materials with a conducting surface, like Weyl Fermi arcs, could host a surface BCD. The bulk and surface BCDs are relevant for the understanding of quantum phenomena such as nonlinear anomalous Nernst effect and the circular photogalvanic effect (CPGE).

Ref:

1. J.-S. You, S. Fang, S.-Y. Xu, E. Kaxiras and T. Low, Phys. Rev. B 98, 121109 (2018).

2. J. I. Facio, D. Efremov, K. Koepernik, J.-S. You, I. Sodemann, and J. van den Brink, Phys. Rev. Lett. 121, 246403 (2018).

3. J. Quereda, TS Ghiasi, J.-S. You, J. van den Brink, BJ van Wees, CH van der Wal, Nature communications 9, 3346 (2018).

4. X.-Q. Yu, Z.-G. Zhu, J.-S. You, T. Low, G. Su, Phys. Rev. B 99, 201410 (2019).

5. D. Wawrzik, J.-S. You, J. I. Facio, J. van den Brink, I. Sodemann, arXiv:2010.10537.

PlaceB102, Gongquan Campuses, NTNU

最後修改時間:2021-02-24 PM 2:13

1234

單位簡介

本系的重點研究領域包括:凝態物理、光電與奈米科學、高能與粒子物理、軟凝態物理與生物物理、原分子光學物理、及物理科學教育等。本系前身為臺灣省立師範學院理化系物理組,成立於民國三十五年(1946年)本校創校之始。民國五十一年(1962年)本系獨立成系,民國六十三年(1974年)成立物理研究所碩士班,民國八十年(1991年)成立研究所博士班。長久以來,本系肩負著培育臺灣中等學校物理科師資的重任,但也不忘在物理學術研究上求新求進步。至今本系培育出的學術人才已有一位中研院院士及近百位中研院研究員及大學教授,各行各業的高科技人材更是不勝枚舉。民國八十三年師資培育法改制後,本系已升級為尖端學術研究、科技應用研發、及中學師資培育三者齊備的系所。

  • 國立臺灣師範大學物理系系友會
  • 系友會線上小額捐款
  • 徐有庠盃-臺灣青年學生物理辯論競賽
  • 國際物理奧林匹亞競賽
  • 公用場地與儀器設施預約系統
  • 學生實習專區
cron web_use_log