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 2019/03/21 - 5/30  Seminar Room #1323  Dr. Hyangtag Lim (KIST) and etc.  Spring 2019: Physics Seminar Serises
공지 2019/02/25 - 06/03  Seminar Room 1501  양용수 교수 (Prof. Yongsoo Yang, KAIST) and etc.  Spring 2019: Physics Colloquium
178 Apr. 19 (Fri.), 02:30 PM  E6-2. 1st fl. #1323  Dr. YoungWoo Nam  A family of finite-temperature electronic phase transitions in graphene multilayers file
177 Apr. 19 (Fri.), 04:00 PM  E6-2. 1st fl. #1323  Dr. Seok Kyun Son  Graphene and hBN heterostructures file
176 Apr. 19(Tue.), 2PM  #1323(E6-2. 1st fl.)  Prof. Mark Koepke, Department of Physics and Astronomy, West Virginia University, USA  Nonlocal collisional electron transport in partially ionized plasma generation, structure, and stability
175 Apr. 27, 2017 (Thu) 4:00 pm  Seminar Room(#1323, E6-2)  Prof.Donghan Lee (Chungnam National Univ.)  반도체 양자점을 이용한 단광자 광원
174 Apr. 28 (Fri.), 02:30 PM  E6-2. 1st fl. #1323  Dr. JeongYoung Park Graduate School of EEWS, KAIST  Hot electron generation at surfaces and its impact to catalysis and renewable energy conversion
173 Apr. 28 (Fri.), 04:00 PM  #1323 (E6-2. 1st fl.)  Dr. Minkyung Jung Research Institute, DGIST  Carbon nanotubes coupled to superconducting impedance matching circuits
172 Apr. 28 (Thu.) 3PM  #2501(E6-2. 2nd fl.)  Dr. Chang Hee Sohn, SEOUL NATIONAL UNIVERSITY  Lattice/Spin/Charge Coupling in 5d Pyrochlore Cd2Os2O7
» Apr. 5 (Tue.), 4PM  E6-2. 1st fl. #1322  Dr. Ara Go, Columbia University  A new impurity solver for multi-orbital systems: adaptive truncation of the Hilbert space
170 Apr.19 (Fri.), 11:00 AM  #1323, E6-2  Dr. Ji-Sang Park  First-principles studies of semiconductors for solar cell applications file
169 April 11 (Thu.), 16:00 PM  #1323, E6-2  Prof. Joo-Hyoung Lee, GIST  Massive screening for cathode active materials using deep neural network file
168 April 11 (Wed), 1:30pm  #1323 (E6-2, 1st fl.)  Dr. Yongsoo Yang  Probing 3D Structure and Physical Properties of Materials at the Single-Atom Level file
167 April 11 (Wed), 4:00pm  #1323 (E6-2, 1st fl.)  Dr. Young-Sik Ra  Non-Gaussian states of multimode light generated via hybrid quantum information processing file
166 April 13 (Fri.), 10am  #1323 (E6-2, 1st fl.)  Dr. Sungkun Hong  Quantum meets Mechanics: from Quantum Information to Fundamental Research file
165 April 23 (Tue.), 4:00 PM  #1323, E6-2  Prof. Johan Chang  From Mott physics to high-temperature superconductivity file
164 April 26 (Fri.), 4:00 PM  #1323, E6-2  Dr. Soonwon Choi  Robust Quantum Metrology using Strongly Interacting Spin Ensembles and Quantum Convolutional Neural Network file
163 April 26 (Tue), 4PM  #1323(1st Floor. E6-2)  Dr. Myung-Ho Bae, Korea Research Institute of Standards and Science  Transport spectroscopy for electronic bands in carbon-based nanomaterials with weak-bond contacts
162 April 4 (Thu.), 16:00 PM  #1323, E6-2  Prof. Su-Hyun Gong  Chiral spin-photon interaction at nanoscale file
161 April 4, 2016 (Mon) - April 8, 2016 (Fri)  KAIST Natural Science Building (E6-2), RM #4314  Dr. Fritz Caspers (CERN)  Radio frequency engineering
160 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
159 April 6 (Fri.), 10:00 AM  #2502, E6  박채연 박사  Entanglement and thermalization in many-body systems: recent progress file