visual
visual

세미나

  • HOME
  • >
  • 소식
  • >
  • 세미나
날짜 2022-10-26 10:00 
일시 Oct. 26th (Wed), 10:00AM 
장소 E6-2 #2502 
연사 Dr. Sun-woo Kim(Univ. of Cambridge) 

물리학과 세미나 안내 드립니다. 관심있는 분들의 많은 참여 부탁드립니다.

 

- Title: Replica Higher-Order Topology of Hofstadter Butterflies in Twisted Bilayer Graphene
- Speaker: Dr. Sun-woo Kim(Univ. of Cambridge)
- Date: Oct. 26th (Wed) 2022, 10:00AM,
- Place: E6-2, #2502
Abstract: 

 

The Hofstadter energy spectrum of twisted bilayer graphene is found to have recursive higher-order topological properties. We demonstrate that higher-order topological insulator (HOTI) phases, characterized by localized corner states, occur as replicas of the original HOTIs to fulfill the self-similarity of the Hofstadter spectrum. We show the existence of the exact flux translational symmetry of twisted bilayer graphene at all commensurate angles. Based on this result, we carefully identify that the original HOTI phase at zero flux is re-entrant at a half-flux periodicity, where the effective twofold rotation is preserved. In addition, numerous replicas of the original HOTIs are found for fluxes without protecting symmetries. Similar to the original HOTIs, replica HOTIs feature both localized corner states and edge-localized real-space topological markers. The replica HOTIs originate from the different interaction scales, namely, intralayer and interlayer couplings, in twisted bilayer graphene. The topological aspect of Hofstadter butterflies revealed in our results highlights symmetry-protected topology in quantum fractals.

번호 날짜 장소 제목
228 2016-03-11 16:00  E6-2. 1st fl. #1501  Jan. Switching handedness of of chiral solitons in Z4 topological insulators
227 2021-04-02 14:30  Online(Zoom)  Quantum computing and entanglement generation using trapped ions and photons
226 2021-05-14 14:30  Online seminar  Electrically tunable spin valve effect in vertical van-der-Waals magnetic tunnel junctions file
225 2015-11-28 10:00  E6-2, #1323  Electron Tunneling Spectroscopy of Single and Bilayer Graphene with Hexagonal Boron Nitride as Tunneling Barrier
224 2022-05-11 16:00  E6-2. #1323 & Zoom  Gravity as a phenomenon in quantum dynamics
223 2022-05-25 16:00  E6-2. 1st fl. #1323 / Zoom  Uncovering New Lampposts for Dark Matter: Continuum or Conformal
222 2019-05-01 16:00  #1323, E6-2  Raman and x-ray scattering study on correlated electron systems: two case examples file
221 2018-04-13 10:00  #1323 (E6-2, 1st fl.)  Quantum meets Mechanics: from Quantum Information to Fundamental Research file
220 2022-09-30 14:30  E6-2. 1st fl. #1323 & Zoom  Putting a spin on the Josephson effect file
219 2022-07-14 15:00  E6 #1501 & Zoom  Pure two-dimensional quantum electron liquid and its phase transition
218 2017-11-03 16:00  #1323 (1st fl., E6-2.)  Expedition to the Kitaev Quantum Spin Liquid: Hunting for Majorana fermions file
217 2016-11-29 16:00  #1323(E6-2. 1st fl.)  Symmetry Protected Kondo Metals and Their Phase Transitions
» 2022-10-26 10:00  E6-2 #2502  Replica Higher-Order Topology of Hofstadter Butterflies in Twisted Bilayer Graphene
215 2016-10-07 13:30  E6-2. #1323(1st fl.)  “Symmetry and topology in transition metal dichalcogenide?”
214 2022-11-24 16:00  E6-2 #1323 & Zoom  Probing fundamental physics by mapping the mm and sub-mm sky
213 2023-09-18 16:00  CAPP Seminar Room C303, Creation Hall, KAIST Munji Campus  [CAPP Seminar] Searching for axions in quantum vacuum birefringence file
212 2019-04-26 16:00  #1323, E6-2  Robust Quantum Metrology using Strongly Interacting Spin Ensembles and Quantum Convolutional Neural Network file
211 2021-12-03 14:30  Zoom webinar  Topological Spin Textures: Skyrmions and Beyond file
210 2019-11-05 16:00  #1323, E6-2  Study on nanomaterials by the development of ultrahigh resolution laser-photoelectron microscopy (PEEM) file
209 2019-11-20 16:00  #5302, E6-2  Correlation between superconducting transition temperature and critical current density in irradiated iron-based superconductors file