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
476 2018-06-22 16:00  #1323, E6-2  Tuning functional properties of BiFeO3 films using strain and growth chemistry file
475 2018-06-22 16:00  #1323, E6-2  Tuning functional properties of BiFeO3 films using strain and growth chemistry file
474 2019-11-28 16:00  #1323, E6-2  Generation of coherent EUV emissions using ultrashort laser pulses file
473 2019-11-14 16:00  #1323, E6-2  Semi-classical model of polariton propagation file
472 2019-10-17 16:00  #1323, E6-2  Top down manipulation of Waves : From Metamaterials, Correlated Disorder, Quantum Analogy, to Digital Processing file
471 2018-05-29 16:00  #1323, E6-2  Investigation on metal nanostructure/semiconductor junction and its applications file
470 2018-10-18 16:00  #1323, E6-2  Applications of nonlinear optics for condensed matter researches file
469 2018-11-29 16:00  #1323, E6-2  양자 칸델라 실현을 위한 단일 광자 발생장치 개발 file
468 2019-09-26 16:00  #1323, E6-2  Entanglement Swapping with Autonomous Polarization-Entangled Photon-Pairs from Warm Atomic Ensemble file
467 2018-07-27 13:30  #1323, E6-2  Magnetic reversal of artificial spin ice file
466 2018-07-27 13:30  #1323, E6-2  Magnetic reversal of artificial spin ice file
465 2018-10-25 16:00  #1323, E6-2  Abelian and non-Abelian dark photons file
464 2019-11-07 16:00  #1323, E6-2  Integrated quantum photonics with solid-state quantum emitters file
463 2018-10-26 16:00  #1323, E6-2  Coexisting triple-point and nodal-line topological magnons and thermal Hall effect in pyrochlore iridates file
462 2018-11-08 16:00  #1323, E6-2  Conformality lost file
461 2019-10-29 14:30  #1323, E6-2  Quantum sensing file
460 2018-09-05 16:00  #1323, E6-2  Shining a light on fractional excitations file
459 2020-02-20 16:00  #1323, E6-2  Unconventional superconductivity in the locally non-centrosymmetric heavy-fermion CeRh2As2 file
458 2019-12-03 16:00  #1323, E6-2  Toward Quantum Materials with Correlated Oxides file
457 2018-10-18 10:00  #1323, E6-2  Understanding membrane protein folding using single-molecule force techniques file