visual
visual

세미나

  • HOME
  • >
  • 소식
  • >
  • 세미나
날짜 2018-04-09 11:00 
일시 Apr. 09 (Mon.), 11:00 AM 
장소 E6-2. 1st fl. #1323 
연사 Dr. Seung-Sup B. Lee 

SRC Seminar

 

 

Doublon-holon origin of the subpeaks at the Hubbard band edges

 

Dr. Seung-Sup B. Lee

Physics Department, LMU Munich

 

Apr. 09 (Mon.), 11:00 AM

E6-2. 1st fl. #1323

 

Abstract:

Dynamical mean-feld theory (DMFT) studies frequently observe a new structure in the local spectral function of the SU(2) Fermi-Hubbard model (i.e., one-band Hubbard model) at half _lling: In the metallic phase close to the Mott transition, subpeaks emerge at the inner edges of the Hubbard bands.

Here we demonstrate that these subpeaks originate from the low-energy e_ective interaction of doublon-holon pairs, by investigating how the correlation functions of doublon and holon operators contribute to the subpeaks [1, 2]. We use the numerical renormalization group (NRG) as a DMFT impurity solver to obtain the correlation functions on the real-frequency axis with improved spectral resolution [3]. A mean-_eld analysis of the low-energy e_ective Hamiltonian [2] provides results consistent with the numerical result.

The subpeaks are associated with a distinctive dispersion that is di_erent from those for quasiparticles and the Hubbard bands. Also, the subpeaks become more pronounced in the SU(N) Hubbard models for larger number N of particle avors, due to the increased degeneracy of doublon-holon pair excitations. Hence we expect that the sub-peaks can be observed in the photoemission spectroscopy experiments of multi-band materials or in the ultracold atom simulation of the SU(N) Hubbard models.

 

[1] S.-S. B. Lee, J. von Delft, and A. Weichselbaum, Phys. Rev. Lett. 119, 236402 (2017).

[2] S.-S. B. Lee, J. von Delft, and A. Weichselbaum, Phys. Rev. B 96, 245106 (2017).

[3] S.-S. B. Lee and A. Weichselbaum, Phys. Rev. B 94, 235127 (2016).

 

Contact: SunYoung Choi, (sunyoungchoi@kaist.ac.kr)

 

Center for Quantum Coherence in Condensed Matter, KAIST

번호 날짜 장소 제목
186 2022-01-18 14:00  KI bldg. 5th fl. Room B501 & Zoom  Data-driven interrogation of biological dynamics: from subcellular interactions to neuronal networks in vivo file
185 2022-01-25 15:00  E6 #1501/online  Emulating twisted double bilayer graphene with a multiorbital optical lattice file
184 2022-01-26 13:00  E6 #1501  An Introduction to Cohomology groups file
183 2022-02-28 16:00  E6, #1501  Spin-based training of optical microscopes
182 2022-03-07 16:00  E6, #1501  Climate Physics and Modelling(우리말강의)
181 2022-03-14 16:00  E6, #1501  Quantitative phase imaging and artificial intelligence: label-free 3D imaging, classification, and inference
180 2022-03-18 11:00  Online seminar  (응집물리 세미나) Illuminating exotic states of matter: Raman spectroscopy as an experimental tool to characterize quantum spin liquids file
179 2022-03-21 16:00  E6, #1501  Multi-wavelength Studies on Relativistic Jets from Gamma-ray Bright Active Galactic Nuclei
178 2022-03-25 11:00  E6-1 #1323  (응집물리 세미나) Hund's metallicity in ruthenate systems file
177 2022-03-28 16:00  E6, #1501  Ultimate-density atomic semiconductor via flat bands
176 2022-03-29 10:00  E6 #1501/zoom, E6 #2502/zoom  Non-reciprocal phase transitions file
175 2022-03-31 10:00  E6 #1501/zoom  Weiss fields for Quantum Spin Dynamics file
174 2022-03-31 16:00  online  (광학분야 특별세미나)Ultrafast time-resolved spectroscopy in topological materials
173 2022-04-01 16:00  Zoom webinar  High-field Electron Transport and Interaction Induced Phenomena in 2D Materials file
172 2022-04-04- 16:00  E6, #1501  New paradigms in Quantum Field Theory
171 2022-04-08 11:00  E6-1 #1323  (응집물리 세미나) Flat-surface-assisted physical phenomena occurring in single crystal metal thin film file
170 2022-04-11 16:00  E6, #1501  Emergence of Statistical Mechanics in Quantum Systems
169 2022-04-13 10:30  E6 #1323/zoom  Harnessing topology and correlations from singularities in 3d-kagome metals
168 2022-04-14 16:00  E6 1323  (광학분야 특별세미나)Holographic tomography of dielectric tensors at optical frequency
167 2022-04-15 11:00  Online seminar  (응집물리 세미나) First-principles studies of polar oxides and their applications file