visual
visual

세미나

  • HOME
  • >
  • 소식
  • >
  • 세미나
날짜 2016-04-05 16:00 
일시 Apr. 5 (Tue.), 4PM 
장소 E6-2. 1st fl. #1322 
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 날짜 장소 제목
347 2015-12-03 16:00  E6-2, #1323  Hybrid solid state spin qubits in wide bandgap semiconductors
346 2022-06-10 16:00  E6-2. 1st fl. #1323  Fe5GeTe2의 나선형 자성특성과 자기저항의 전류밀도 의존성 연구 file
345 2017-03-24 16:00  #1323 (1st fl. E6-2)  Graphene based nano electronics and nano electromechanics; focusing on precise control of nano structures for studying accurate physical properties
344 2016-09-29 16:00  E6-2 #1323 (1st floor)  Large-scale Silicon Photonic MEMS Switches
343 2015-07-15 14:00  E6-2,1323  Electronic and optical properties of titanate-based oxide superlattices
342 2019-06-17 10:30  #1323, E6-2  Chiral Spintronics file
341 2019-04-19 16:00  E6-2. 1st fl. #1323  Graphene and hBN heterostructures file
340 2023-09-21 16:00  CAPP Seminar Room C303, Creation Hall, KAIST Munji Campus  [CAPP seminar] Axion Magnetic Resonance file
339 2023-10-11 16:00  E6-2, Rm2502  [High Energy Theory Seminar] Axion Magnetic Resonance
338 2016-01-26 14:00  E6-2, #1323  Electrochemistry on Nano- and Atomic Levels: Scanning Probe Microscopy Meets Deep Data
337 2019-03-29 14:30  E6-2. 1st fl. #1323  Epitaxial Multifunctional Oxide Thin Films for Novel Electronics file
336 2018-06-01 11:00  E6-2. 1st fl. #1323  Topological phases in low-dimensional quantum materials file
335 2019-10-29 16:00  #1323 (E6-2, 1st fl.)  Particles and Gravity via String Geometry file
334 2018-04-09 11:00  E6-2. 1st fl. #1323  Doublon-holon origin of the subpeaks at the Hubbard band edges file
333 2019-10-31 10:00  #1323 (E6-2, 1st fl.)  Kondo meets Hubbard: Impurity physics for correlated lattices file
332 2022-06-10 14:30  E6-2. 1st fl. #1323  Combinatorial strategy for condensed matter physics: study on rare earth hexaborides thin films file
331 2020-02-13 16:30  E6-6, #119  Enhanced Light-Matter Interactions in Graphene with Noble Metal Plasmonic Structures file
330 2019-11-20 16:00  #5302, E6-2  Correlation between superconducting transition temperature and critical current density in irradiated iron-based superconductors file
329 2019-11-05 16:00  #1323, E6-2  Study on nanomaterials by the development of ultrahigh resolution laser-photoelectron microscopy (PEEM) file
328 2021-12-03 14:30  Zoom webinar  Topological Spin Textures: Skyrmions and Beyond file