visual
visual

세미나

  • HOME
  • >
  • 소식
  • >
  • 세미나
장소 E6-2. 1st fl. #1322 
일시 Apr. 5 (Tue.), 4PM 
연사 Dr. Ara Go, Columbia University 

"A new impurity solver for multi-orbital systems: adaptive truncation of the Hilbert space"

 

Apr. 5 (Tue.), 4PM, E6-2. 1st fl. #1322
Dr. Ara Go, Columbia University

 

The exact diagonalization (ED) has many attractive advantages as an impurity solver for the dynamical mean-field theory (DMFT). It solves the impurity Hamiltonians with any types of interaction in contrast to the quantum Monte Carlo, which suffers from the severe sign problem in low symmetry situation. However, the ED approximates the continuous bath to a finite quantum mechanical problem to reduce the system size, so that the total number of orbitals is less than 14. This is insufficient, to treat most multi-orbital systems via the DMFT. To overcome this limit, we first adapt the configuration interaction (CI) as an impurity solver. We show the computed optical conductivity through this method is in excellent agreement with the experiment at gap edge. We have further developed adaptive truncations of the Hilbert space, which can handle much larger impurity Hamiltonians without loosing the advantages of the ED. We benchmark the one-dimensional Hubbard model and show that this impurity solver can obtain sufficiently accurate Green functions of impurity Hamiltonian with 24 electronic orbitals. The solvable system size in this method is larger than twice of the ED limit, and this capability enlarges the DMFT applications to many unexplored problems. I also discuss the possible applications, focussing on the multi-orbital systems with low symmetry.

 

Contact: MyungJoon Han, Physics Dept., (mj.han@kaist.ac.kr)

번호 일시 장소 연사 제목
공지 2019/09/18 - 12/5  Seminar Room #1323  Prof. David Schuster and etc.  Fall 2019: Physics Seminar Serises
공지 2019/09/02 - 12/09  Seminar Room 1501  이호성 박사 (한국표준과학연구원) and etc.  Fall 2019: Physics Colloquium
325 2018년 9월 7일 (금), 3PM  학술문화관 (E9), 2층 양승택 오디토리움  Prof. Martin Head-Gordon, UC Berkeley  Recent developments in density functional theory: From new functionals to the nature of the chemical bond file
324 5월 17일(화), 11:00 ~ 12:00  창의학습관(E11), 406호  방준혁 박사(Korea Basic Science Institute, KBSI)  The CERN Resonant WISP Search: Development, Results and Lesson-Learned
323 Dec. 13-14(Wed.-Thu.) 13:30 PM  자연과학동 대형강의실 (1501호)  장기주 교수 외 9명  KAIST-KIAS Joint Workshop in Theoretical Sciences 개최 file
322 August 1, 2018 at 11:00AM  양분순 빌딩 (E16-1) 207호  이대열 교수, 예일대 석좌교수  Future of AI: Is the brain a computer? file
321 Sep.28. 5:30 pm  Zoom webinar  Burkard Hillebrands (TU Kaiserslautern, Germany)  KAIST Global Forum for Spin and Beyond(Fourth Forum) file
320 Sep. 14(Mon) 17:30~  Zoom webinar  Teruo Ono (Kyoto U. Japan)  KAIST Global Forum for Spin and Beyond (Third Forum) file
319 Sep. 22nd 9:30 AM  Zoom webinar  Prof. Xu Yi (Univ. of Virginia, USA)  Physics and applications of soliton microcombs(Quantum- & Nano-Photonics) file
318 Aug, 25(Tue), 20:00~  Zoom webinar  Mark D. Stiles (NIST, USA)  KAIST Global Forum for Spin and Beyond (Second Forum) file
317 Aug. 17(Mon), 20:00~  Zoom webinar  Mark D. Stiles (NIST, USA)  Using magnetic tunnel junctions to compute like the brain file
316 July 2, 2020 (Thursday)  Zoom Video Conference Seminar  Dr. Emmanuel Flurin (CEA Saclay)  An irreversible qubit-photon coupling for the detection of itinerant microwave photons file
315 Sep. 24(Thu), 09:00~, Sep. 24(Thu), 16:00 ~  Zoom Video  Akash V. Dixit (University of Chicago), Dr. Boris Ivanov (Novosibirsk State Technical University)  (CAPP/IBS)Searching for Dark Matter with a Superconducting Qubit , Cryogenic Microwave Circuit Development at the NSTU file
314 Jan.28(Thu), 03:00PM  Zoom  Yaroslav Tserkovnyak (UCLA)  Topological Transport of Deconfined Hedgehogs in Magnets file
313 Feb.15(Mon), 05:00PM  Zoom  Yoshichika Otani(Tokyo Univ.)  Magnetic Cluster Octupole Domain evolutation in chiral antiferromagnets file
312 Feb. 2(Tue) 2:30 PM  Zoom  Prof. Sangsik Kim (Texas Tech University, USA)  Quantum- & Nano-Photonics 세미나(Integrated Nanophotonics with Metamaterials, Microcomb, and Atomic Systems) file
311 December 2(Wed), 10:00AM  Zoom  Prof. Rakshya Katiwada (Illinois Institute of Technology)  Recent progress in Axion Dark Matter eXperiment (ADMX) technology file
310 Sep. 11(Fri), 14:00~  zoom  이관형교수/SNU, 이상윤교수/GIST  SRC Seminar file
309 Dec.10(Thu), 01:55 PM  Zoom  Yin Wen (University of Tokyo)  Consistency of Boltzmann equation and light dark matter from inflaton decay
308 Dec.9(Wed), 10:00AM  Zoom  Prof. Andrew Geraci (Northwestern University)  Searching for the QCD axion with the ARIADNE experiment file
307 Apr. 27, 2017 (Thu) 4:00 pm  Seminar Room(#1323, E6-2)  Prof.Donghan Lee (Chungnam National Univ.)  반도체 양자점을 이용한 단광자 광원
306 2017/03/06 - 05/29  Seminar Room 1501  이종봉 박사 (POSTECH) 외  Spring 2017: Physics Colloquium file