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)
334 2021-07-29 14:00    Gravitationally Induced Dark Sector and Inflationary Dynamics file
333 2021-06-22 17:00    Spintronics meets Quantum Materials file
332 2021-06-11 16:00    Pseudogap in surface-doped black phosphorus file
331 2021-06-11 14:30    Engineering sound waves and vibrations in multi-mode nanomechanical systems file
330 2021-06-08 10:00    Photonic crystal devices for sensing file
329 2021-05-27 16:00    찾아가는 물리연구 현장(유럽 입자물리학연구소 소개) file
328 2021-05-17 17:00    Spin current generation and detection in uniaxial antiferromagnets file
327 2021-05-14 16:00    Spatial and temporal separation of environmental dephasing sources from solid-state quantum emitters file
326 2021-05-14 14:30    Electrically tunable spin valve effect in vertical van-der-Waals magnetic tunnel junctions file
325 2021-04-19 19:00    Evidence of Electrical Switching in Antiferromagnets and Coherent Spin Pumping file
324 2021-04-09 10:00    Integrated Lithium Niobate Photonics file
323 2021-04-02 16:00    Van der Waals heterostructures for orbital gating-based phototransistors and electronic spectroscopy
322 2021-04-02 14:30    Quantum computing and entanglement generation using trapped ions and photons
321 2021-03-25 16:00    Search for dark matter axion with Rydberg atoms file
320 2021-03-02 16:00    Sensitive terahertz detection with graphene-based transistors file
319 2021-02-17 09:00    석학 대중 강연 및 강의 시리즈 file
318 2021-02-15 17:00    Magnetic Cluster Octupole Domain evolutation in chiral antiferromagnets file
317 2021-02-02 14:30    Quantum- & Nano-Photonics 세미나(Integrated Nanophotonics with Metamaterials, Microcomb, and Atomic Systems) file
316 2021-01-28 18:00    Quantum metamaterials: concept, theory, prototypes and possible applications file
315 2021-01-28 15:00    Topological Transport of Deconfined Hedgehogs in Magnets file