visual
visual

세미나

  • HOME
  • >
  • 소식
  • >
  • 세미나
날짜 2022-10-26 10:00 
연사  
장소 E6-2 #2502 

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 연사 제목
공지 2025-02-24 16:00    2025년 봄학기 콜로키움 안내
공지 2025-02-27 16:00    2025년 봄 물리학과 특별세미나 (광학/응집물리 분야)
425 2022-10-06 13:00    Counting States with Global Symmetry
424 2022-08-12 10:00    Twisted Bilayer Magnets file
423 2022-08-12 10:00    Twisted Bilayer Magnets file
422 2016-04-26 16:00    Transport spectroscopy for electronic bands in carbon-based nanomaterials with weak-bond contacts
421 2018-05-11 16:00    암페어 단위 재정의와 단전자 펌프 소자 개발 file
420 2025-04-22 16:00  Dr. Nanse Esaki (The University of Tokyo)  Spin Nernst and thermal Hall effects of topological triplons in quantum dimer magnets on the maple-leaf and star lattices file
419 2016-06-01 10:30    Welcome to Nature Photonics
418 2018-07-02 15:00    High Precision Magnetic Field Measurement for the Muon g-2 Experiment file
417 2015-10-16 15:00    High Magnetic Fields to Probe the sub-eV range of Particle/Astroparticle Physics - From the OSQAR experiments at CERN up to new perspectives at LNCMI-Grenoble
416 2018-11-09 14:30    Moiré superlattices – from twisted bilayer graphene to quasicrystal file
415 2024-05-30 10:00    Quasiperiodic Effects in Quasicrystals
414 2024-05-16 14:30    [Astrophysics Seminar] Observational Cosmology with Superconducting Sensors
413 2022-03-29 10:00    Non-reciprocal phase transitions file
412 2022-03-31 10:00    Weiss fields for Quantum Spin Dynamics file
411 2020-10-15 17:00    Time crystals, quasicrystals, and time crystal dynamics in the superfluid universe file
410 2023-05-03 16:00    Probing microscopic origins of axions by the chiral magnetic effect
409 2022-11-09 16:00    Radio Astronomy, Radio Interferometry, and Multi-wavelength Studies on Relativistic Jets
408 2017-06-02 16:00    Maxwell's demon in quantum wonderland file
407 2015-12-03 16:00    Hybrid solid state spin qubits in wide bandgap semiconductors
406 2025-01-08 16:00  Dr. SangEun Han  Quantum impurity model for two-stage multipolar ordering and Fermi surface reconstruction