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
공지 2022-10-24 16:00  E6 #1501(공동강의실)  Physics Colloquim(Fall 2022)
공지 2022-09-21 10:30  E6-1 #1501  [Update 세미나 영상] Distinguished Lecture 'The Magic of Moiré Quantum Matter' Prof. Pablo Jarillo-Herrero(Department of Physics, MIT)
공지 2022-11-11 11:00  E6-2 #1323  [Update 세미나영상] (응집물리 세미나) Honeycomb oxide heterostructures for quantum spin liquid
공지 2022-10-28 11:00  E6-2 #1323  [Update 세미나영상] (응집물리 세미나) Machine-Learning-Guided Prediction models and Materials discovery for high Tc cuprates
공지 2022-10-07 11:00  E6-2 #1323  [Update 세미나 영상] (응집물리 세미나) Competing orders in a vanadium-based kagome metal monolayer
공지 2022-09-23 11:00  E6-2 #1323  [Update 세미나 영상] (응집물리 세미나) Steady Floquet-Andreev states in graphene Josephson junctions
공지 2022-09-22 11:00  E6-1 #1323  2022 가을학기 응집물리 및 광학 세미나 전체 일정
113 2022-04-08 11:00  E6-1 #1323  (응집물리 세미나) Flat-surface-assisted physical phenomena occurring in single crystal metal thin film file
112 2018-11-21 15:00  #1323, E6-2  Engineering topological quantum physics at the atomic scale file
111 2016-06-14 15:00  #1323 (E6-2 1st fl.)  No-Insulation High Temperature Superconductor Magnet Technology for Compact, Reliable, and Low-Cost High Field DC Magnets
110 2019-12-18 16:00  #1323, E6-2  Road to Higher Tc Superconductivity file
109 2019-07-16 16:00  Rm. 1323 (E6-2)  2019 Physics Distinguished Lecture file
108 2019-07-10 16:00  Academic Cltural Complex (E9) 5층 스카이라운지  Public Lectures file
107 2018-10-04 16:00  #1323, E6-2  Engineering light absorption in an ultrathin semiconductor metafilm file
106 2019-12-05 16:00  #1323, E6-2  Subwavelenth Photonic Devices: From Single Photon Sources to Solar Cell file
105 2019-05-24 16:00  #1323, E6-2  Infrared spectroscopy study on metal-insulator transitions in layered perovskite iridates file
104 2019-04-04 16:00  #1323, E6-2  Chiral spin-photon interaction at nanoscale file
103 2021-02-17 09:00  Online  석학 대중 강연 및 강의 시리즈 file
102 2018-11-22 15:00  E6 Room(#1323)  Experimental and Computational Study on Physical Properties based on Granular System file
101 2018-05-31 16:00  #1323, E6-2  Dynamic control of optical properties with gated-graphene metamaterials file
100 2020-10-09 09:00  https://kaist.zoom.us/j/85161896513?pwd=U3pwWFFZaWVRamxDZUR5REhNeVk0UT09  Quantum Many-Body Simulation file
99 2017-04-05 12:00  Room 101, Creative Learning Bldg.(E11)  2017년 4월 첫수 융합포럼 개최 안내(물리학과 & 원자력 및 양자공학과 공동 개최)/The First Wednesday Multidisciplinary Forum in April 2017 organized by Dept. of Physics & Dept. of Nuclear & Quantum Engineering file
98 2020-09-22 09:30  Zoom webinar  Physics and applications of soliton microcombs(Quantum- & Nano-Photonics) file
97 2017-11-08 13:00  #5318 (E6-2. 5th fl.)  “Emergent exotic quasiparticles in quantum spin liquids” file
96 2017-09-13 16:00  #1323 (E6-2. 1st fl.)  An Introduction to Quantum Spin Liquids file
95 2017-09-12 16:00  #1323 (E6-2. 1st fl.)  Exact Solution for the Interacting Kitaev Chain at Symmetric Point file
94 2018-05-17 13:30  E6-2. 1st fl. #1323  Quantum Spin Liquid in Kitaev Materials file