visual
visual

세미나

  • HOME
  • >
  • 소식
  • >
  • 세미나
날짜 2016-09-21 16:00 
일시 4pm, Sep. 21 (Wed. 
장소 E6-2. #2502(2nd fl.) 
연사 Dr. Henrik Johannesson , University of Gothenburg (Sweden) and Beijing Computational Science Research Center (China) 

Entanglement probe of two-impurity Kondo physics

 

4pm, Sep. 21 (Wed.), E6-2. #2502(2nd fl.)
Dr. Henrik Johannesson , University of Gothenburg (Sweden) and Beijing Computational Science Research Center (China)


The two-impurity Kondo model has bearings on a number of topical problems, from heavy-fermion physics to spin-based quantum computing. In this talk I will review what is known about the model and also present a novel approach to its study, initiated in a collaboration with A. Bayat, S. Bose, and P. Sodano [1]. Specifically, we propose that real-space properties of the model can be obtained from an effective spin model where two single-impurity Kondo spin chains are joined via an RKKY interaction between the two impurity spins. We then use the Density Matrix Renormalization Group (DMRG) to study its features, using two complementary quantum-entanglement measures, the negativity and the von Neumann entropy. This nonperturbative approach enables us to uncover the Kondo screening cloud and its enhancement in the limit of large ferromagnetic RKKY coupling, thus corroborating a long-standing conjecture of ”Kondo resonance narrowing" for effectively large impurity spins. In a follow-up work [2], we extended our approach to study the entanglement spectrum of the model, and obtained the Schmidt gap, i.e. the difference between the two largest eigenvalues of the reduced density matrix. The Schmidt gap is found to signal the quantum phase transition between the Kondo and RKKY phases, in effect serving as an order parameter, correctly predicting the known scaling exponent for the Kondo crossover length at the critical point. Time permitting, I will briefly discuss also some more recent applications of our approach, to the study of local quantum quenches [3], the entanglement structure of the two-channel Kondo model [4], and impurity quantum thermodynamics [5].

 

[1] A. Bayat et al., Phys. Rev. Lett. 109, 066403 (2012)
[2] A. Bayat et al., Nat. Comm. 5, 3784 (2014)
[3] A. Bayat et al., Phys. Rev. B 92, 155141 (2015)
[4] B. Alkurtass et al., Phys. Rev. B 93, 081106(R) (2016)
[5] A. Bayat et al., Phys. Rev. B 93, 201106(R) (2016)

Contact: Heung Sun Sim, Physics Dept., (hs_sim@kaist.ac.kr)

번호 날짜 장소 제목
262 2022-09-29 16:00  E6-2 #1323  (광학분야 세미나) Ultrafast THz Field-Induced Nonlinear Optics
261 2023-04-27 16:00  E6-2 #1323  (광학분야 세미나)On-chip spectrometers based on CMOS image sensors
260 2023-01-12 16:00  E6-2 #1323  Spin wavepackets in the Kagome ferromagnet Fe3Sn2: propagation and precursors
259 2024-01-24 15:00  E6-2 #1323  Determination of single molecule loading rate during mechanotransduction file
258 2022-11-17 16:00  E6-2 #1323  (광학분야 세미나) Ultrastructural and Spectroscopic Studies by Super-Resolution Fluorescence Microscopy
257 2023-01-11 16:00  E6-2 #1323  Non-abelian anyons and graph gauge theory on a superconducting processor, Eun-Ah Kim (Cornell University/Ewha Womans University)
256 2023-05-12 11:00  E6-2 #1323  (응집물리 세미나)Interlayer conductivity and plasmon in weakly coupled layered systems
255 2022-09-22 16:00  E6-2 #1323  (광학분야 세미나) Quasi-particle-like optical vortices in magnetic materials
254 2023-04-14 12:00  E6-2 #1323  (응집물리 세미나)Exotic quantum phenomena in two-dimensional materials file
253 2023-01-11 11:00  E6-2 #1323  Directly proving magnetoelastic coupling in a soft ferromagnet using Lorentz 4D-STEM file
252 2023-01-12 14:40  E6-2 #1323  JILA 1D Wannier-Stark optical lattice clock file
251 2022-11-11 11:00  E6-2 #1323  [Update 세미나영상] (응집물리 세미나) Honeycomb oxide heterostructures for quantum spin liquid file
250 2023-03-17 11:00  E6-2 #1323  (응집물리 세미나)Operando electron microscopy investigation of domain dynamics in twisted van der Waals materials file
249 2023-05-18 16:00  E6-2 #1323  (광학분야 세미나)Dielectric metasurfaces for optimized optical system and spatial light modulators
248 2023-05-19 11:00  E6-2 #1323  (응집물리 세미나)Dipole condensations in Tilted Bose-Hubbard Chains
247 2022-10-27 16:00  E6-2 #1323  (광학분야 세미나) Cavity optomechanical systems for quantum transduction
246 2022-10-07 11:00  E6-2 #1323  [Update 세미나 영상] (응집물리 세미나) Competing orders in a vanadium-based kagome metal monolayer file
245 2023-09-07 12:00  E6-2 #1323  2023 가을학기 광학분야 및 응집물리 특별세미나 전체 일정 file
244 2023-05-26 11:00  E6-2 #1323  (응집물리 세미나)Spectral Analyses of Stochastic Charge Trapping in Oxide Heterostructures file
243 2022-09-23 11:00  E6-2 #1323  [Update 세미나 영상] (응집물리 세미나) Steady Floquet-Andreev states in graphene Josephson junctions file