visual
visual

세미나

  • HOME
  • >
  • 소식
  • >
  • 세미나
날짜 2016-04-05 16:00 
연사  
장소 E6-2. 1st fl. #1322 

"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 연사 제목
공지 2025-02-24 16:00    2025년 봄학기 콜로키움 안내
공지 2025-02-27 16:00    2025년 봄 물리학과 특별세미나 (광학/응집물리 분야)
485 2024-03-20 16:00    [High-Energy Theory Seminar] Black hole states at finite N
484 2024-01-03 11:00    Interplay of Strong Correlations, Topology, and Disorder in 2D Quantum Matters
483 2023-09-13 16:00    [High Energy Theory Seminar] Cosmic Birefringence from Dark Photon
482 2022-06-23 11:00    JILA’s search for the electron’s Electric Dipole Moment (eEDM) to probe physics beyond the standard model file
481 2022-01-11 15:00    Ultrafast optical studies on CDW collective modes of the Weyl-CDW (TaSe4)2I file
480 2024-01-16 14:00    Dimer Physics and Superconductivity in La3Ni2O7
479 2020-02-20 16:00    Unconventional superconductivity in the locally non-centrosymmetric heavy-fermion CeRh2As2 file
478 2023-12-19 16:00    [High Energy Theory Seminar] Non-invertible symmetries, leptons, quarks, and why multiple generations
477 2022-12-13 11:00    Art of thin film engineering toward topological quantum computation file
476 2016-09-29 16:00    2016 Fall, Physics Seminar Serises file
475 2023-01-11 11:00    Directly proving magnetoelastic coupling in a soft ferromagnet using Lorentz 4D-STEM file
474 2021-11-02 16:00    Metrology of Band Topology via Resonant Inelastic X-ray Scattering file
473 2015-07-16 16:00    KAIST Physics Distinguished Lecture
472 2017-11-28 16:00    Physics after the lab and the desk: Your work in PRL file
471 2025-03-11 12:00  Rak-Kyeong Seong (UNIST)  The AI Revolution for Quantum Fields and Strings: A Case Study
470 2022-04-15 11:00    (응집물리 세미나) First-principles studies of polar oxides and their applications file
469 2017-04-27 16:00    반도체 양자점을 이용한 단광자 광원
468 2019-09-18 16:00    Exploring Synthetic Quantum Matter in Superconducting Circuits file
467 2019-07-25 16:00    Band topology of twisted bilayer graphene file
466 2015-10-16 16:00    Fluctuations of entropy production in partially masked electric circuits