visual
visual

세미나

  • HOME
  • >
  • 소식
  • >
  • 세미나
날짜 2016-09-21 16:00 
연사  
장소 E6-2. #2502(2nd fl.) 

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 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)
305 2024-03-13 16:00    [High-Energy Theory Seminar] The Schwarzschild Black Hole from Perturbation Theory to all Orders
304 2019-07-21 12:00    Challenges and Opportunities in Theoretical Particle Physics 2019 file
303 2022-01-25 15:00    Emulating twisted double bilayer graphene with a multiorbital optical lattice file
302 2019-09-10 15:00    (2+1) D Duality Web from 3D Euclidean Lattice file
301 2022-01-12 11:00    Spectroscopic study of trapped ions towards probing dark matter and new physics file
300 2024-11-30 10:30  Joon Young Park  Towards probing topological phases in Corbino-geometry Josephson junctions on a topological insulator surface
299 2022-05-19 15:00    (광학분야 특별세미나)Development of a multimodal optical system for improved disease diagnosis
298 2022-05-19 15:00    (광학분야 특별세미나)Development of a multimodal optical system for improved disease diagnosis
297 2023-07-10 16:00    Electronic structures of magnetic and non-magnetic ordering in d- and f-electrons systems
296 2019-08-16 14:00    Multiferroic and Magnetoelectric Effects by Tailoring Interfacial Chemistry and Physics in Correlated Oxides file
295 2021-05-17 17:00    Spin current generation and detection in uniaxial antiferromagnets file
294 2019-05-08 16:00    Imaging valley dependent electron transport in 2D semiconductors file
293 2019-05-08 16:00    Imaging valley dependent electron transport in 2D semiconductors file
292 2025-03-14 14:00  Jeonghee Rho (SETI Institute)  JWST Imaging and Spectroscopy of the Supernova Remnant Cassiopeia A and Molecule and Dust Formation file
291 2024-12-17 15:00  Isaac H. Kim  Learning state preparation circuit for quantum phases of matter (Isaac H. Kim, UC Davis)
290 2019-06-27 14:00    Gapless Kitaev Spin Liquid to Loop and String Gases file
289 2016-06-16 16:00    Quantum information processing using quantum dots and photonic crystal cavities
288 2020-12-11 16:00    Atomic and electronic reconstruction at van der Waals interface in twisted 2D materials
287 2024-02-16 10:00    Optical conductivity of superconducting states driven by Van Hove singularities
286 2019-08-01 14:00    Low-density Superconductivity in SrTiO3 Probed by Planar Tunneling Spectroscopy file