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)
614 2009-02-23 16:00    Physics Colloquium : 2009 Spring file
613 2009-09-07 16:00    Physics Colloquium : 2009 Fall file
612 2009-10-21 16:00    Interdimensional Universality of Dynamic Interfaces
611 2010-02-08 16:00    Physics Ciolloquium : 2010 Spring file
610 2010-02-14 16:00    Physics Colloquium - 2011 Spring file
609 2010-09-06 16:00    Physics Colloquium : 2010 Fall file
608 2011-05-16 16:00    Photonics with surface plasmon polaritons
607 2011-09-03 16:00    Physics Colloquium : 2011 Fall file
606 2012-02-13 16:00    Physics Colloquium : 2012 Spring
605 2012-04-02 16:00    A new route to ferroelectricity in magnetic spinels: a case of Co2MnO4
604 2013-03-11 16:00    Physics Colloquium : 2013 Spring
603 2013-09-09 16:00    Physics Colloquium : 2013 Fall
602 2014-03-10 16:00    Physics Colloquium : 2014 Spring file
601 2014-05-28 17:00    부품소재산업이 미래다
600 2014-12-22 14:00    Dynamics of molecular motors: Power stroke vs Brownian ratchet file
599 2015-03-04 12:00    Bioimaging and Biosensing Using Near-Infrared Fluorescence file
598 2015-03-09 16:00    Physics Colloquium : 2015 Spring file
597 2015-03-13 14:00    The 15th Innovative Workshop on Soft/Bio Materials file
596 2015-06-03 12:00    The First Wednesday Multidisciplinary Forum file
595 2015-07-15 14:00    Electronic and optical properties of titanate-based oxide superlattices