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)
445 2018-11-22 15:00    Experimental and Computational Study on Physical Properties based on Granular System file
444 2021-02-17 09:00    석학 대중 강연 및 강의 시리즈 file
443 2019-04-04 16:00    Chiral spin-photon interaction at nanoscale file
442 2023-11-22 10:00    [High Energy Theory Seminar] Exact Quantum Algorithms to Recognize Quantum Phases of Matter
441 2019-05-24 16:00    Infrared spectroscopy study on metal-insulator transitions in layered perovskite iridates file
440 2023-06-16 13:00    Quantum critical states under extreme conditions
439 2019-12-05 16:00    Subwavelenth Photonic Devices: From Single Photon Sources to Solar Cell file
438 2018-10-04 16:00    Engineering light absorption in an ultrathin semiconductor metafilm file
437 2019-07-10 16:00    Public Lectures file
436 2019-07-16 16:00    2019 Physics Distinguished Lecture file
435 2019-12-18 16:00    Road to Higher Tc Superconductivity file
434 2016-06-14 15:00    No-Insulation High Temperature Superconductor Magnet Technology for Compact, Reliable, and Low-Cost High Field DC Magnets
433 2018-11-21 15:00    Engineering topological quantum physics at the atomic scale file
432 2022-04-08 11:00    (응집물리 세미나) Flat-surface-assisted physical phenomena occurring in single crystal metal thin film file
431 2019-10-29 10:00    Unconventional Spin Transport in Quantum Materials file
430 2021-02-02 14:30    Quantum- & Nano-Photonics 세미나(Integrated Nanophotonics with Metamaterials, Microcomb, and Atomic Systems) file
429 2018-11-23 15:00    Entanglement string and Spin Liquid with Holographic duality file
428 2018-06-22 10:00    Success in Research Career file
427 2016-04-18 15:30    First Principles Approaches for Intermolecular Interactions: From Gas-Phase Dimers to Liquid Water and Molecular Crystal Polymorphism file
426 2020-12-02 10:00    Recent progress in Axion Dark Matter eXperiment (ADMX) technology file