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
68 Dec. 3 (Fri.), 04:00 PM  Zoom webinar  Dr. Hyejin Jang (Seoul National University)  Nonequilibrium Heat Transport in Elemental Metals Probed by an Ultrathin Magnetic Thermometer file
67 May 13 (Fri.) 4 PM  E6. #1501(1st fl.)  Dr. Hosub Jin, Dept. of Physics, UNIST  Graphene analogue in (111)- BaBiO3 bilayer heterostructures for topological electronics
66 Nov. 16 (Wed), 4p.m.  #1323(E6-2. 1st fl.)  Dr. Heung-Sik Kim , University of Toronto  Realizing Haldane Model in Fe-based Honeycomb Ferromagnetic Insulators
65 Jan.9 (Wed.), 04:00 PM  E6-2. 2nd fl. #2501  Dr. Heung-Sik Kim  Molecular Mott state in the deficient spinel GaV4S8 file
64 4pm, Sep. 21 (Wed.  E6-2. #2502(2nd fl.)  Dr. Henrik Johannesson , University of Gothenburg (Sweden) and Beijing Computational Science Research Center (China)  Entanglement probe of two-impurity Kondo physics
63 Jun 24 (Mon) 11:00  E6-2, #1323  Dr. Henning Schomerus  Topological photonic anomalies file
62 2015/10/23, 3PM  E6-2, #5318  Dr. Helmut Soltner (Forschungszentrum Juelich)  Development of a Rogowski Coil as a new beam position monitor
61 Apr. 2 (Fri.), 04:00 PM  Online(Zoom)  Dr. Heejun Yang (KAIST)  Van der Waals heterostructures for orbital gating-based phototransistors and electronic spectroscopy
60 May 19 (Thu) 4PM  #1323(E6-2, 1st fl.)  Dr. Heedeuk Shin, POSTECH  Nonlinear/quantum optical effect in silicon nano-photonics
59 Sep. 22, 2016(Thu), 3:30 PM  #1323(E6-2, 1st fl.)  Dr. Haiyang Yan (Institute of Nuclear Physics and Chemistry)  Polarized 3He, Polarized Neutrons and New Interactions beyond the Standard Model
58 Sep. 22, 2016(Thu), 3:30 PM  #1323(E6-2, 1st fl.)  Dr. Haiyang Yan (Institute of Nuclear Physics and Chemistry)  Polarized 3He, Polarized Neutrons and New Interactions beyond the Standard Model
57 2015/09/14, 2PM  E6-2. 2nd fl. #2501  Dr. Hae Ja Lee ( Stanford University, SLAC )  Ultrafast X-ray Studies on Dynamics Matter in Extreme Conditions
56 Dec. 7 (Fri.), 02:30 PM  E6-2. 1st fl. #1323  Dr. Gyung Min Choi  Spin generation from heat and light in metals file
55 Sep. 22 (Fri.), 04:00 PM  E6-2. 1st fl. #1323  Dr. GilHo Lee / Department of Physics, POSTECH  Unexpected Electron-Pairing in Integer Quantum Hall Effect file
54 Sep. 22 (Fri.), 02:30 PM  E6-2. 1st fl. #1323  Dr. GilHo Lee / Department of Physics, POSTECH  Quantum Electronic Transport in Graphene Hybrid Nanostructures file
53 October 25 (Thu.), 4:00 PM  #1323, E6-2  Dr. Gang Li  Abelian and non-Abelian dark photons file
52 Nov. 1st (Tue), 10:30AM  #1323(E6-2 1st fl.)  Dr. Gadi Eisenstein, Technion  Time scale dependent dynamics in InAs/InP quantum dot gain media
51 April 4, 2016 (Mon) - April 8, 2016 (Fri)  KAIST Natural Science Building (E6-2), RM #4314  Dr. Fritz Caspers (CERN)  Radio frequency engineering
50 May 24 (Tue) 4 PM  E6-2. #1323(1st fl.)  Dr. Euyheon Hwang, SKKU Advanced Institute of Nanotechnology, Sung Kyung Kwan University  Electronic and magnetic properties of 2D transition-metal thiophosphates and tunability of magnetic order with carrier density
49 Jun. 2 (Fri.), 02:30 PM  E6-2. 1st fl. #1323  Dr. Euyheon Hwang(황의헌)  Quasiparticle Interference and Fourier transform scanning tunneling spectroscopy in WTe2 (Weyl semimetal) file