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
217 2022-08-12 10:00  E6-1 #1323  Twisted Bilayer Magnets file
216 2022-03-25 11:00  E6-1 #1323  (응집물리 세미나) Hund's metallicity in ruthenate systems file
215 2022-08-18 10:00  E6-1 #1323  Disorder-driven phase transition in the second-order non-Hermitian skin effect
214 2022-05-20 11:00  E6-1 #1323  (응집물리 세미나) Exploration of new polymorphs in van der Waals crystals
213 2022-09-22 11:00  E6-1 #1323  2022 가을학기 응집물리 및 광학 세미나 전체 일정 file
212 2014-12-22 14:00  E6, Rm1319  Dynamics of molecular motors: Power stroke vs Brownian ratchet file
211 2023-09-27 16:00  E6, Rm#2501  Chiral Magnets: Domain-Wall Skyrmions and String Theory Realization
210 2023-06-26 11:00  E6, Rm#1323  Quantum computing on magnetic racetracks with flying domain wall qubits
209 2023-08-24 11:00  E6, Rm#1323  Advancing magnonic metamaterials: spin waves in nanomagnetic arrays
208 2016-03-07 16:00  E6, 1501  Physics Colloquium : 2016 Spring file
207 2015-09-07 16:00  E6, 1501  Physics Colloquium : 2015 Fall file
206 2015-03-09 16:00  E6, 1501  Physics Colloquium : 2015 Spring file
205 2015-09-15 16:00  E6, 1501  Physics Colloquium : 2014 Fall file
204 2014-03-10 16:00  E6, 1501  Physics Colloquium : 2014 Spring file
203 2013-09-09 16:00  E6, 1501  Physics Colloquium : 2013 Fall
202 2013-03-11 16:00  E6, 1501  Physics Colloquium : 2013 Spring
201 2012-04-02 16:00  E6, 1501  A new route to ferroelectricity in magnetic spinels: a case of Co2MnO4
200 2012-02-13 16:00  E6, 1501  Physics Colloquium : 2012 Spring
199 2011-09-03 16:00  E6, 1501  Physics Colloquium : 2011 Fall file
198 2011-05-16 16:00  E6, 1501  Photonics with surface plasmon polaritons