visual
visual

세미나

  • HOME
  • >
  • 소식
  • >
  • 세미나
장소 E6-2. #2502(2nd fl.) 
일시 4pm, Sep. 21 (Wed. 
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 일시 장소 연사 제목
공지 Sep.22 2022  E6-1 #1323    2022 가을학기 응집물리 및 광학 세미나 전체 일정
198 Jan 12th (Wed), 11:00 AM  Zoom and E6 #1323  Joonseok Hur (MIT)  Spectroscopic study of trapped ions towards probing dark matter and new physics file
197 Sep10(Tue), 15:00  #2502, E6-2  Jun Ho Son  (2+1) D Duality Web from 3D Euclidean Lattice file
196 Jan. 25th (Tue), 15:00  E6 #1501/online  Junhyun Lee (Rutgers, the State University of New Jersey)  Emulating twisted double bilayer graphene with a multiorbital optical lattice file
195 July 21 - August 2  E6-2,# 5318  Junmou Chen/Thomas Flacke/Kaoru Hagiwara/Junichi Kanzaki/Chris Kelso/Jeong Han Kim/Kyoungchul Kong/Gabriel Lee/Hye-Sung Lee/Ian Lewis  Challenges and Opportunities in Theoretical Particle Physics 2019 file
194 August. 6th (TUE), 14:00  E6 Room(#1323)  Kanghyun Chu  Visualization of in-plane piezoresponse vector fields file
193 2012/02/13-05/14  E6, 1501  Kenji Ohmori (Photo-Molecular Science, IMS)  Physics Colloquium : 2012 Spring
192 Jun 1 (Wed) 4 PM  #1323(E6-2 1st fl.)  Kil-Byoung Chai, Caltech  Laboratory experiments relevant to mesospheric clouds, Saturn’s rings & astrophysical jets
191 Jul 3rd, 2019 (Wed)  E6-2, 2501  Kyung Soo Choi  Many-body quantum electrodynamis (QED) with atoms and photons: A new platform for quantum optics" file
190 July 26, 2018 at 14:00  Room 5318, KAIST Natural Sciences Lecture Hall(E6).  Manki Kim (Department of Physics, Cornell University)  Inflation in String Theory and Backreaction file
189 Aug. 17(Mon), 20:00~  Zoom webinar  Mark D. Stiles (NIST, USA)  Using magnetic tunnel junctions to compute like the brain file
188 Aug, 25(Tue), 20:00~  Zoom webinar  Mark D. Stiles (NIST, USA)  KAIST Global Forum for Spin and Beyond (Second Forum) file
187 January 23, 2019  Rm. C303, Creation Hall (3F), Munji Campus  Mikko Mottonen  Ultrasensitive Microwave Bolometer: Opportunity for Axion Detectors file
186 Apr. 13(Wed.) 10:30Am  E6 #1323/zoom  Mingu Kang (Max Planck POSTECH Korea Research Initiative)  Harnessing topology and correlations from singularities in 3d-kagome metals
185 Dec. 11 (Fri.), 02:30 PM  online  Myung Hwa Jung(Sogang Univ.)  Antisymmetric interlayer exchange coupling in magnetic multilayers
184 Nov.26(Thu), 04:00PM  Online(Zoom)  Myung-Ki Kim  2020 가을학기 광학분야 특별세미나(Light Engineering Beyond the Diffraction Limit)
183 Oct. 17th (Mon) 11:00 AM  #1323,(E6-2, 1st fl.)  Nguyen Quang Liem, Institute of Materials Science, VAST, Viettnam  IMS and examples of the studies on optoelectronic materials
182 8/19 (Mon), 10:00~11:30, 8/22 (Thur), 10:00~11:30  Rm. 1322, E6-2  Nicolas Treps  Tutorials on Multimode Quantum Optics in the Continuous Variable Regime file
181 Sep. 21(Wed.) 10:30~12:00  E6-1 #1501  Pablo Jarillo-Herrero(Department of Physics, MIT)  Distinguished Lecture 'The Magic of Moiré Quantum Matter' file
180 Aug. 8th (Mon), 14:00  E6-2 #2502  Prof. Soonwon Choi(MIT)  Classical Shadow Tomography for Analog Quantum Simulators
179 Dec.9(Wed), 10:00AM  Zoom  Prof. Andrew Geraci (Northwestern University)  Searching for the QCD axion with the ARIADNE experiment file