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
447 2019-01-09 16:00  E6-2. 2nd fl. #2501  Molecular Mott state in the deficient spinel GaV4S8 file
446 2016-11-16 16:00  #1323(E6-2. 1st fl.)  Realizing Haldane Model in Fe-based Honeycomb Ferromagnetic Insulators
445 2016-05-13 16:00  E6. #1501(1st fl.)  Graphene analogue in (111)- BaBiO3 bilayer heterostructures for topological electronics
444 2021-12-03 16:00  Zoom webinar  Nonequilibrium Heat Transport in Elemental Metals Probed by an Ultrathin Magnetic Thermometer file
443 2018-07-27 15:00  Room 5318, KAIST Natural Sciences Lecture Hall(E6).  Muon g-2 in the 2HDM and MSSM: comprehensive numerical analysis and absolute maxima file
442 2018-07-27 15:00  Room 5318, KAIST Natural Sciences Lecture Hall(E6).  Muon g-2 in the 2HDM and MSSM: comprehensive numerical analysis and absolute maxima file
441 2023-11-16 16:00  E6-2(Natural Science B/D). 1st fl. #1323  Electric-field control of emergent phenomena in correlated oxide thin films
440 2022-07-14 14:15  E6 #1501 & Zoom  Hund and electronic correlations in ruthenium-based systems
439 2022-01-26 13:00  E6 #1501  An Introduction to Cohomology groups file
438 2018-10-12 16:00  E6-2. 1st fl. #1323  Direct observation of a two-dimensional hole gas at oxide interfaces file
437 2022-11-18 14:30  E6-2. 1st fl. #1323 & Zoom  Kondo cloud condensation in a highly-doped semiconductor metal file
436 2018-12-26 16:00  E6-2. 1st fl. #1323  Brane-like defect in 3D toric code file
435 2019-07-31 16:00  E6-2, #1323  Features of ballistic superconducting graphene file
434 2018-07-12 17:00  Room 5318, KAIST Natural Sciences Lecture Hall(E6)  The MilliQan Experiment: Search for Milli-Charged Particles at the LHC
433 2016-12-09 13:30  #1323(E6-2. 1st fl.)  Entanglement area law in strongly-correlated systems
432 2023-11-23 16:00  E6-2(Natural Science B/D). 1st fl. #1323  Deciphering the Enigma of Quantum Materials by X-ray Scattering and Spectroscopy
431 2019-10-16 16:00  #1323 (E6-2, 1st fl.)  Emergent black holes and monopoles from quantum fields file
430 2022-07-14 13:30  E6 #1501 & Zoom  Electronic structure and anomalous transport properties of topological materials by first principle calculation
429 2016-11-24 16:00  #1323(E6-2. 1st fl.)  Harmonic oscillator physics with single atoms in a state-selective optical potential
428 2015-09-07 15:00  E6-2. 1st fl. #1318  Advanced Optical Materials and Devices at NRL