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
37 Jul. 07 (Thu.) 2PM  #1323(E6-2. 1st fl.)  Dr. Eun Ah Kim, CORNELL UNIV.  Let there be topological superconductors
36 2015/08/04, 11PM  B501, Room Red, KI bldg. 5nd fl.  Dr. Eric Jin Ser Lee(Univ. of Manitoba, Canada)  Propagation of ultrasound through two- and three-dimensional strongly scattering media
35 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
34 October 18 (Thu.), 10:00 AM  #1323, E6-2  Dr. Duyoung Min  Understanding membrane protein folding using single-molecule force techniques file
33 #1323(E6-2. 1st fl.)  Jul. 10th (Mon), 4pm  Dr. Duk Young Kim Los Alamos National Laboratory  “Intertwined Orders in a Heavy-fermion metal” file
32 Nov. 9 (Fri.), 04:00 PM  E6-2. 1st fl. #1323  Dr. Donghun Lee  Quantum sensing and imaging with diamond defect centers for nano-scale spin physics file
31 Nov. 04 (Fri), 3:00 PM  E6-2. #1323(1st fl.)  Dr. Dohun Kim, Department of Physics and Astronomy, SNU  Quantum information experiments using few electron spins in semiconductors
30 September 5 (Wed.), 16:00 PM  #1323, E6-2  Dr. Dirk Wulferding  Shining a light on fractional excitations file
29 June 22 (Fri.), 04:00 PM  #1323, E6-2  Dr. Daniel Sando  Tuning functional properties of BiFeO3 films using strain and growth chemistry file
28 June 22 (Fri.), 04:00 PM  #1323, E6-2  Dr. Daniel Sando  Tuning functional properties of BiFeO3 films using strain and growth chemistry file
27 Oct. 12 (Fri.), 02:30 PM  E6-2. 1st fl. #1323  Dr. Daniel Kyungdeock Park  Quantum Advantage in Learning Parity with Noise file
26 May 16, 2016 (Mon) 4PM  #1323(E6-2, 1st Fl.)  Dr. Daniel Bowring , Fermi National Accelerator Laboratory  Tuning microwave cavities with biased nonlinear dielectrics for axion searches
25 2015/11/19, 4PM  E6-2, #1323  Dr. Daesu Lee (University of Wisconsin-Madison)  Emergent Collective Phenomena and Functions at Reduced Dimensions
24 2015/12/02, 4PM  E6-2, #1323  Dr. Dae-Jeong Kim (Dept. of Physics and Astronomy, University of California, Irvine)  Samarium Hexaboride: Is it a Topological insulator?
23 Oct. 07 (Fri), 4:00 PM  E6-2. #1323(1st fl.)  Dr. Choong Hyun Kim,IBS-CCES, Seoul National University  “Tilt engineering of 4d and 5d transition metal oxides?”
22 Apr. 08 (Fri.), 4:00 PM  E6-2. 5st fl. #1501  Dr. Changyoung Kim, SEOUL NATIONAL UNIV.  Spectroscopic studies of iron-based superconductors : what have we learned?
21 Sep. 4 (Tue), 02:30 PM  E6-2. 2st fl. #2502  Dr. Changmin Lee, MIT  Ultrafast time- and angle-resolved photoemission spectroscopy (tr-ARPES) with extreme ultraviolet laser pulses file
20 December 13 (Fri.), 1:00 PM  #2501, E6-2  Dr. Chang-Jong Kang  Computational Material Designs: Current Status and Future Directions file
19 Apr. 28 (Thu.) 3PM  #2501(E6-2. 2nd fl.)  Dr. Chang Hee Sohn, SEOUL NATIONAL UNIVERSITY  Lattice/Spin/Charge Coupling in 5d Pyrochlore Cd2Os2O7
18 Oct. 18 (Tue.), 1:30 PM  1st fl. #1323(E6-2)  Dr. Chan-Ho Yang, Department of Physics, KAIST  "Visualization of oxygen vacancy in motion and the interplay with electronic conduction"