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
71 2016-11-1 10:30    Time scale dependent dynamics in InAs/InP quantum dot gain media
70 2016-04-04 09:30    Radio frequency engineering
69 2023-06-14 16:00    [CAPP seminar] EMC at CERN file
68 2023-06-15 16:00    [CAPP Seminar] Cryogenic electronics for ion traps file
67 2016-05-24 16:00    Electronic and magnetic properties of 2D transition-metal thiophosphates and tunability of magnetic order with carrier density
66 2017-06-02 14:30    Quasiparticle Interference and Fourier transform scanning tunneling spectroscopy in WTe2 (Weyl semimetal) file
65 2017-09-22 13:00    Superconductor-metal-insulator transition in thin Tantalum films file
64 2016-07-07 14:00    Let there be topological superconductors
63 2015-08-04 11:00    Propagation of ultrasound through two- and three-dimensional strongly scattering media
62 2020-07-02 16:00    An irreversible qubit-photon coupling for the detection of itinerant microwave photons file
61 2023-03-02 11:00    Probing Anomalies of Non-Invertible Symmetries with Symmetry TFTs
60 2023-07-19 16:00    [High-Energy Theory Seminar]Deriving the Simplest Gauge-String Duality
59 2018-10-18 10:00    Understanding membrane protein folding using single-molecule force techniques file
58 2023-04-28 11:00    Tkachenko wave: From the modern field theory viewpoint
57 2022-05-25 14:00    Atomic-level insights into ferroelectric switching and preferred orientation of ultrathin hafnia file
56 2017-07-10 16:00    “Intertwined Orders in a Heavy-fermion metal” file
55 2020-11-20 14:30    Lumpy Cooper pairs in an iron-based superconductor
54 2022-11-18 16:00    Qubits, new experimental tools for physics file
53 2018-11-09 16:00    Quantum sensing and imaging with diamond defect centers for nano-scale spin physics file
52 2022-01-17 14:00    Five Lectures on Observational Probes of Dark Energy file