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
15 2014/05/28, PM5  KI Building, Matrix Hall  이웅범 대표이사(LG이노텍)  부품소재산업이 미래다
14 2017/03/06 - 05/29  Seminar Room 1501  이종봉 박사 (POSTECH) 외  Spring 2017: Physics Colloquium file
13 November 8 (Thu.), 16:00 PM  #1323, E6-2  이종완 박사  Conformality lost file
12 2009/09/07-11/30  E6, 1501  이주영박사(KIAS) 외  Physics Colloquium : 2009 Fall file
11 2015/10/14, 6PM  KAIST Munji Campus Supex Hall  이창환 교수 (부산대학교 물리학과)  인터스텔라 영화 속의 물리 file
10 2019/09/02 - 12/09  Seminar Room 1501  이호성 박사 (한국표준과학연구원) and etc.  Fall 2019: Physics Colloquium file
9 May 21 (Tue.), 4:00 PM  #5318, E6-2  임준원 박사  Classification of flat bands according to the band-crossing singularity of Bloch wave functions file
8 Dec. 13-14(Wed.-Thu.) 13:30 PM  자연과학동 대형강의실 (1501호)  장기주 교수 외 9명  KAIST-KIAS Joint Workshop in Theoretical Sciences 개최 file
7 Oct. 15, 4pm  (https://kaist.zoom.us/j/93997220310)  정현석 교수님 (SNU)  Towards resource-efficient and fault-tolerant quantum computation with nonclassical light
6 2017/03/21 - 06/08  Seminar Room 1323  조길영 박사(KAIST) 외  Spring 2017: Physics Seminar Serises file
5 2010/09/06-12/06  E6, 1501  조호진기자(조선일보) 외  Physics Colloquium : 2010 Fall file
4 2009/10/21, 4PM  E6, 1501  최석봉교수(서울대)  Interdimensional Universality of Dynamic Interfaces
3 2010/02/08-05/03  E6, 1501  최인수교수(서울대) 외  Physics Ciolloquium : 2010 Spring file
2 2015/03/09-06/08  E6, 1501  최현용교수(연세대) 외12명  Physics Colloquium : 2015 Spring file
1 2010/02/14-05/09  E6, 1501  황철주(주성엔지니어링 사장) 외  Physics Colloquium - 2011 Spring file