• HOME
  • >
  • 소식
  • >
  • 세미나
장소 #5318(E6-2. 5th fl.) 
일시 AUG. 31 (Thu.), 2 PM 
연사 Prof. Hiroaki Ishizuka (The University of Tokyo) 

“Berry phase and nonlinear response: photocurrent in noncentrosymmetric insulators and Weyl semimetals”

Prof. Hiroaki Ishizuka (The University of Tokyo)

AUG. 31 (Thu.), 2 PM / #5318(E6-2. 5th fl.)


Berry phase is one of the important keywords to understand non-trivial quantum effects. In condensed matter physics, the Berry phase often shows up in transport phenomena (e.g., quantum and anomalous Hall effects) and is considered as a keyword to understand topological properties of non-interacting fermion systems. While most of such studies have focused on the equilibrium states or linear responses in close to the equilibrium, a recent study on the photogalvanic effects have pointed out the relation between the Berry phase and photogalvanic effects in noncentrosymmetric insulators where inter-band transitions take an essential role [1-3]; it is named shift current as it is related to the shift of the Wannier function. So far, however, no observable consequences that distinguish this phenomenon from the conventional mechanism is known. In this talk, we theoretically explored the basic properties of shift current focusing on the distinction between the conventional and shift current mechanisms. 

To theoretically study the photocurrent, we employed a Keldysh Green’s function formalism combined with Floquet theory. Using a large size numerical calculation, we study how the photocurrent changes by the local excitation, i.e., when only a part of the system is irradiated by the light. We show that, for the shift current, the magnitude of the current does not depend on the position of the light [4]. This is in contrast to the conventional mechanism, where the photocurrent is expected to be larger at the edge of the sample while it is suppressed when the light is at the center. Such behavior is consistent with the photocurrent recently observed in a noncentrosymmetric organic solid [5].

In the latter half of the talk, we discuss the effect of Berry phase on the photocurrent in Weyl semimetals [6,7]. We show that the Berry phase associated with the Weyl nodes induce a similar phenomenon to the adiabatic pump, resulting in a dissipation-less photocurrent. We find that the photocurrent appears only with the circularly polarized lights. This mechanism may potentially explain the photocurrent observed in TaAs [8].


[1] W. Kraut and R. von Blatz, Phys. Rev. B 19, 1548 (1979); ibid. 23, 5590 (1981). 

[2] J. E. Sipe and A. I. Shkrebtii, Phys. Rev. B 61, 5337 (2000).

[3] T. Morimoto and N. Nagaosa, Science Adv. 2, e1501524 (2016).

[4] H. Ishizuka and N. Nagaosa, New J. Phys. 19, 033015 (2017).

[5] M. Nakamura, et al., Nature Commun. 8, 281 (2017).

[6] H. Ishizuka et al., Phys. Rev. Lett. 117, 216601 (2016).

[7] H. Ishizuka et al., Phys. Rev. B 95, 245211 (2017).

[8] Q. Ma et al., preprint (arXiv: 1705.00690).


Contact: Eun Gook Moon, Physics Dept., (

20170831_Hiroaki Ishizuka.pdf

번호 일시 장소 연사 제목
공지 2018/09/20 - 11/29  Seminar Room #1323  손주혁 교수(서울시립대 물리학과) and etc.  Fall 2018: Physics Seminar Serises
공지 2018/08/27 - 12/03  Seminar Room 1501  김승중 교수 (KAIST) and etc.  Fall 2018: Physics Colloquium
214 Aug. 16 (Wed.), 4 PM  #1322 (E6-2. 1st fl.)  Prof. Noejung Park (UNIST)  Phonon-driven spin-Floquet valleytro-magnetism file
213 Mar. 24 (Fri.), 4:00 PM  #1323 (1st fl. E6-2)  Dr. SangWook Lee  Graphene based nano electronics and nano electromechanics; focusing on precise control of nano structures for studying accurate physical properties
212 Mar. 24 (Fri.), 2:30 PM  #1323 (1st fl. E6-2).  Dr. MahnSoo Choi  Topological Dynamics
211 Nov. 3 (Fri.), 2:30 PM  #1323 (1st fl., E6-2.)  Dr. MinChul Lee(Department of Applied Physics, Kyung Hee Univ.)  Quantum Resistor-Capacitor Circuit with Majorana Edge States file
210 Nov. 3 (Fri.), 4:00 PM  #1323 (1st fl., E6-2.)  Dr. SungDae Ji (Max Planck POSTECH/Hshinchu Center (MPK))  Expedition to the Kitaev Quantum Spin Liquid: Hunting for Majorana fermions file
209 June 14, 2016 (Tue) 3PM  #1323 (E6-2 1st fl.)  Prof. Seungyong Hahn, Florida State University  No-Insulation High Temperature Superconductor Magnet Technology for Compact, Reliable, and Low-Cost High Field DC Magnets
208 April 13 (Fri.), 10am  #1323 (E6-2, 1st fl.)  Dr. Sungkun Hong  Quantum meets Mechanics: from Quantum Information to Fundamental Research file
207 April 11 (Wed), 1:30pm  #1323 (E6-2, 1st fl.)  Dr. Yongsoo Yang  Probing 3D Structure and Physical Properties of Materials at the Single-Atom Level file
206 April 11 (Wed), 4:00pm  #1323 (E6-2, 1st fl.)  Dr. Young-Sik Ra  Non-Gaussian states of multimode light generated via hybrid quantum information processing file
205 Jun. 2 (Fri.), 4:00 PM  #1323 (E6-2. 1st fl.)  Dr. Sang Wook Kim  Maxwell's demon in quantum wonderland file
204 Apr. 28 (Fri.), 04:00 PM  #1323 (E6-2. 1st fl.)  Dr. Minkyung Jung Research Institute, DGIST  Carbon nanotubes coupled to superconducting impedance matching circuits
203 July. 14 (Fri.), 3:00 PM  #1323 (E6-2. 1st fl.)  Dr. Jun Hyun Lee / University of Maryland  Chiral anomaly in disordered Weyl semimetals file
202 Sep. 12 (Tue.), 4 PM  #1323 (E6-2. 1st fl.)  Prof. Yi. Zhou (The Zhejiang Univ.)  Exact Solution for the Interacting Kitaev Chain at Symmetric Point file
201 Sep. 13 (Wed.), 4 PM  #1323 (E6-2. 1st fl.)  Prof. Yi. Zhou (The Zhejiang Univ.)  An Introduction to Quantum Spin Liquids file
200 Sep. 26 (Tue.), 11AM  #1323 (E6-2. 1st fl.)  Dr. Yukiaki Ishida / ISSP, University of Tokyo  Time-resolved ARPES study of Dirac and topological materials
199 Nov. 28 (Tue.), 4:00 PM  #1323 (E6-2. 1st fl.)  Samindranath Mitra, Editor at Physical Review Letters  Physics after the lab and the desk: Your work in PRL file
198 April 26 (Tue), 4PM  #1323(1st Floor. E6-2)  Dr. Myung-Ho Bae, Korea Research Institute of Standards and Science  Transport spectroscopy for electronic bands in carbon-based nanomaterials with weak-bond contacts
197 Jun 1 (Wed) 4 PM  #1323(E6-2 1st fl.)  Kil-Byoung Chai, Caltech  Laboratory experiments relevant to mesospheric clouds, Saturn’s rings & astrophysical jets
196 Nov. 1st (Tue), 10:30AM  #1323(E6-2 1st fl.)  Dr. Gadi Eisenstein, Technion  Time scale dependent dynamics in InAs/InP quantum dot gain media
195 Oct. 27th(Thu) 4PM  #1323(E6-2)  Dr. 이 강 희, KAIST, Mechnical Engineering  Terahertz Metal Optics