visual
visual

세미나

  • HOME
  • >
  • 소식
  • >
  • 세미나
날짜 2024-10-21 13:00 
연사 Geonhwi Hwang (Hokkaido University) 
장소 E6-2 #3441 

 

Non-Hermitian topological phases have recently garnered increasing attention since they possess richer topological properties than those in Hermitian systems. In the theory of topological phases, the bulk-edge correspondence (BEC) takes one of the most important roles. For the topological phases characterized by the point gap, which is an energy gap unique to non-Hermitian systems, the BEC has been established for the systems with periodic boundary systems (PBC), semi-infinite boundary conditions (SIBC), and open boundary conditions (OBC) as detailed in [1]. Further, in Hermitian systems, the BEC is extended to the junction systems consisting of two subsystems with independent topological invariant. In the non-Hermitian system, however, the BEC has not been discussed for the junction systems so far. In this work, we clarify the BEC for point gap topological phases in junction systems [2]. As shown in Fig. 1, we consider a one-dimensional junction system with PBC where two ends of a subsystem are connected to those of the other subsystem so that the whole system forms a ring geometry. Each subsystem has asymmetric hopping terms and its own point-gap topological invariant. We confirm that the spectrum for the junction system with PBC appears on the complex-energy plane where the difference in winding number for each subsystem is non-trivial. We further study eigenstates in the junction systems and find that unique ''non-Hermitian proximity effects'' occur near the interface. These results establish the BEC for the point-gap topological phases in junction systems with PBC, which is regarded as a natural extension inferred from the BEC in Hermitian systems. We also examine the junction system with OBC then confirm that the spectrum for the junction system with OBC appears on and inside the spectrum for the corresponding junction system with PBC. We further extend the BEC for point-gap topological phases to multi-segmented junction systems, which may provide deeper insights into spectrum and localization phenomena across various models.

 
[1] N. Okuma, K. Kawabata, K. Shiozaki, and M. Sato, Phys. Rev. Lett. 124, 086801 (2020).
[2] G. Hwang and H. Obuse, Phys. Rev. B 108, L121302 (2023).
 
Contact: Sungbin Lee(sungbin@kaist.ac.kr)

 

번호 날짜 연사 제목
공지 2026-03-09 16:00    2026년 봄학기 콜로키움
공지 2026-03-05 16:00    2026년 봄학기 물리학과 특별세미나 (광학/응집물리 분야)
378 2022-10-04 16:00    Distinguishing 6d (1, 0) SCFTs
377 2025-09-19 13:00  Prof. Chris. A Marianetti (Columbia University)  Towards an efficient first-principles theory of strongly correlated electron materials file
376 2015-03-04 12:00    Bioimaging and Biosensing Using Near-Infrared Fluorescence file
375 2019-05-03 11:00    Exotic Magnetism file
374 2014-12-22 14:00    Dynamics of molecular motors: Power stroke vs Brownian ratchet file
373 2025-07-21 11:00  Prof. Chang-Jong Kang (Chungnam National University)  Electronic Structure and Physical Properties of an Altermagnetic System: A Case Study of MnTe file
372 2019-05-30 16:00    Tuning the excitonic properties of semiconductors with light-matter interactions file
371 2023-10-11 16:00    [CAPP seminar] Particle Physics with Neutrinos file
370 2018-07-09 14:00    The principles of collective learning file
369 2023-06-01 16:00    Hall viscosity and topological phenomena
368 2021-03-25 16:00    Search for dark matter axion with Rydberg atoms file
367 2016-08-04 14:30    Relational Logic (with applications to Quantum Mechanics, String Theory, Cosmology, Neutrino Oscillations, Statistical Mechanics)
366 2022-03-25 11:00    (응집물리 세미나) Hund's metallicity in ruthenate systems file
365 2024-05-28 11:00  Prof. Ara Go (Department of Physics, Chonnam National University)  동적평균장 이론 소개
364 2019-08-22 16:00    Physics and Applications in Nanoelectronics and Nonomechanics file
363 2020-12-09 10:00    Searching for the QCD axion with the ARIADNE experiment file
362 2025-04-21 16:00  Prof. Ambrose Sungseok Seo (Univ of Kentucky)  Condensed matter physics? All you gotta do is just meet me at the ... file
361 2025-10-23 14:00  Prof. Alfredo De Rossi (Thales Research and Technology)  40 years of nonlinear optics in photonic crystals file
360 2022-08-08 14:00    Classical Shadow Tomography for Analog Quantum Simulators
359 2026-05-12 15:00  Prof. Ro, Sunghan (Dept. of Physics, Harvard Univ.)  Multipole-conserving diffusion file