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
259 2015-12-03 16:00  E6-2, #1323  Hybrid solid state spin qubits in wide bandgap semiconductors
258 2015-11-24 16:00  E6-2, #1323  Topology-based understanding of spin dynamics in inhomogeneously magnetized systems
257 2015-11-23 13:30  E6-2, #1323  What's Beyond the Standard Model? Lessons from Run I and what might come in Run II
256 2015-11-28 10:00  E6-2, #1323  Electron Tunneling Spectroscopy of Single and Bilayer Graphene with Hexagonal Boron Nitride as Tunneling Barrier
255 2015-12-01 16:00  E6-2, #1323  Introducing extra dimensions to spectroscopic studies of advanced quantum materials
254 2015-12-11 13:30  E6-2, #1323  Quantum spin liquid in the 1/3 depleted triangular lattice Ba3(Ru1-xIrx)Ti2O9
253 2015-12-11 15:45  E6-2, #1323  Dynamical mean field theory studies on heavy fermion system
252 2016-01-11 16:00  E6-2, #1323  Mott Physics in the Strong Spin-Orbit Coupling Regime
251 2016-01-26 14:00  E6-2, #1323  Electrochemistry on Nano- and Atomic Levels: Scanning Probe Microscopy Meets Deep Data
250 2016-09-29 16:00  E6-2, #1323  2016 Fall, Physics Seminar Serises file
249 2019-06-24 11:00  E6-2, #1323  Topological photonic anomalies file
248 2019-07-25 16:00  E6-2, #1323  Band topology of twisted bilayer graphene file
247 2019-07-31 16:00  E6-2, #1323  Features of ballistic superconducting graphene file
246 2022-09-15 13:00  E6-2, #1323  AdS black holes: a review
245 2023-07-12 11:00  E6-2, #1323  Study of spin-1/2 antiferromagnetic kagome Heisenberg model by symmetric projected entangled simplex states
244 2023-07-11 11:00  E6-2, #1323  Ordered phases, non-Fermi liquid, and quantum criticality driven by entanglement between multipoles and conduction electrons
243 2023-07-19 16:00  E6-2, #1323  [High-Energy Theory Seminar]Deriving the Simplest Gauge-String Duality
242 2023-07-18 11:00  E6-2, #1323  Non-Hermitian Casimir Effect of Magnons
241 2023-12-19 16:00  E6-2, #1323  [High Energy Theory Seminar] Non-invertible symmetries, leptons, quarks, and why multiple generations
240 2024-01-03 11:00  E6-2, #1323  Interplay of Strong Correlations, Topology, and Disorder in 2D Quantum Matters