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
119 Dec. 12th (Mon)  1:30p.m. #1323(E6-2. 1st fl.)  Dongjoon Song , AIST  “Possible symmetry in the phase diagrams of electron- & hole-doped cuprate high-Tc superconductors”
118 DEC. 11 (Tue), 04:00 PM  E6-2. 1st fl. #1323  Prof. Hiroshi Shinaoka  Natural compact representation of Matsubara Green’s functions: applications to analytic continuation and quantum many-body simulations file
117 Dec. 11 (Fri.), 04:00 PM  online  Hyobin Yoo(Sogang Univ.)  Atomic and electronic reconstruction at van der Waals interface in twisted 2D materials
116 Dec. 11 (Fri.), 02:30 PM  online  Myung Hwa Jung(Sogang Univ.)  Antisymmetric interlayer exchange coupling in magnetic multilayers
115 Dec 27 (Fri), 3:00 PM  #5318, E6-2  Han Gyeol Suh  The superconducting order parameter puzzle of Sr2RuO4 file
114 August. 6th (TUE), 14:00  E6 Room(#1323)  Kanghyun Chu  Visualization of in-plane piezoresponse vector fields file
113 August. 1st (Thu), 14:00  E6 Room(#1323)  Hyeok Yoon  Low-density Superconductivity in SrTiO3 Probed by Planar Tunneling Spectroscopy file
112 August. 16th (Fri), 14:00  E6 Room(#1323)  Jinxing Zhang  Multiferroic and Magnetoelectric Effects by Tailoring Interfacial Chemistry and Physics in Correlated Oxides file
111 August. 14th (Wed.), 4:00PM,  Rm. 1323, E6  Prof. Nicolas Treps  Quantum Optics, at the heart of quantum metrology and quantum information file
110 August 27 (Tue.), 4:00PM  Rm. 1323, E6  Hiroshi Eisaki  Critical current properties of Fe-based superconductors file
109 August 1, 2018 at 11:00AM  양분순 빌딩 (E16-1) 207호  이대열 교수, 예일대 석좌교수  Future of AI: Is the brain a computer? file
108 Aug. 4, 2016 (Thu.), 2:30 pm  KAIST Natural Science Building (E6-5), EDU 3.0 Room(1st fl.)  Prof. Argyris Nicolaidis  Relational Logic (with applications to Quantum Mechanics, String Theory, Cosmology, Neutrino Oscillations, Statistical Mechanics)
107 AUG. 31 (Thu.), 2 PM  #5318(E6-2. 5th fl.)  Prof. Hiroaki Ishizuka (The University of Tokyo)  “Berry phase and nonlinear response: photocurrent in noncentrosymmetric insulators and Weyl semimetals” file
106 Aug. 17(Mon), 20:00~  Zoom webinar  Mark D. Stiles (NIST, USA)  Using magnetic tunnel junctions to compute like the brain file
105 Aug. 16 (Wed.), 4 PM  #1322 (E6-2. 1st fl.)  Prof. Noejung Park (UNIST)  Phonon-driven spin-Floquet valleytro-magnetism file
104 Aug, 25(Tue), 20:00~  Zoom webinar  Mark D. Stiles (NIST, USA)  KAIST Global Forum for Spin and Beyond (Second Forum) file
103 April 6, 2017 (Thu), 4:00 pm  IBS CAPP seminar room, Creation Hall (3F), KAIST Munji Campus  Prof. Youngjoon Kwon (Yonsei University)  For whom the Belle tolls
102 April 6, 2016 (Wed), 3:30 PM  E6-2, RM #1323  Dr. Andrei Matlashov (Los Alamos National Laboratory)  Superconducting Quantum Interference Devices for Precision Detection
101 April 6 (Fri.), 10:00 AM  #2502, E6  박채연 박사  Entanglement and thermalization in many-body systems: recent progress file
100 April 5th 2017, 12:00 ~ 13:00  Room 101, Creative Learning Bldg.(E11)  Prof. Wonho Choe(Dept. of Physics),Prof. Young-chul GHIM(Dept. of Nuclear & Quantum Engineering)  2017년 4월 첫수 융합포럼 개최 안내(물리학과 & 원자력 및 양자공학과 공동 개최)/The First Wednesday Multidisciplinary Forum in April 2017 organized by Dept. of Physics & Dept. of Nuclear & Quantum Engineering file