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 2019/09/18 - 12/5  Seminar Room #1323  Prof. David Schuster and etc.  Fall 2019: Physics Seminar Serises
공지 2019/09/02 - 12/09  Seminar Room 1501  이호성 박사 (한국표준과학연구원) and etc.  Fall 2019: Physics Colloquium
307 2018년 9월 7일 (금), 3PM  학술문화관 (E9), 2층 양승택 오디토리움  Prof. Martin Head-Gordon, UC Berkeley  Recent developments in density functional theory: From new functionals to the nature of the chemical bond file
306 5월 17일(화), 11:00 ~ 12:00  창의학습관(E11), 406호  방준혁 박사(Korea Basic Science Institute, KBSI)  The CERN Resonant WISP Search: Development, Results and Lesson-Learned
305 Dec. 13-14(Wed.-Thu.) 13:30 PM  자연과학동 대형강의실 (1501호)  장기주 교수 외 9명  KAIST-KIAS Joint Workshop in Theoretical Sciences 개최 file
304 August 1, 2018 at 11:00AM  양분순 빌딩 (E16-1) 207호  이대열 교수, 예일대 석좌교수  Future of AI: Is the brain a computer? file
303 Aug. 17(Mon), 20:00~  Zoom webinar  Mark D. Stiles (NIST, USA)  Using magnetic tunnel junctions to compute like the brain file
302 Aug, 25(Tue), 20:00~  Zoom webinar  Mark D. Stiles (NIST, USA)  KAIST Global Forum for Spin and Beyond (Second Forum) file
301 Sep. 14(Mon) 17:30~  Zoom webinar  Teruo Ono (Kyoto U. Japan)  KAIST Global Forum for Spin and Beyond (Third Forum) file
300 Sep. 22nd 9:30 AM  Zoom webinar  Prof. Xu Yi (Univ. of Virginia, USA)  Physics and applications of soliton microcombs(Quantum- & Nano-Photonics) file
299 Sep.28. 5:30 pm  Zoom webinar  Burkard Hillebrands (TU Kaiserslautern, Germany)  KAIST Global Forum for Spin and Beyond(Fourth Forum) file
298 July 2, 2020 (Thursday)  Zoom Video Conference Seminar  Dr. Emmanuel Flurin (CEA Saclay)  An irreversible qubit-photon coupling for the detection of itinerant microwave photons file
297 Sep. 24(Thu), 09:00~, Sep. 24(Thu), 16:00 ~  Zoom Video  Akash V. Dixit (University of Chicago), Dr. Boris Ivanov (Novosibirsk State Technical University)  (CAPP/IBS)Searching for Dark Matter with a Superconducting Qubit , Cryogenic Microwave Circuit Development at the NSTU file
296 Sep. 11(Fri), 14:00~  zoom  이관형교수/SNU, 이상윤교수/GIST  SRC Seminar file
295 Apr. 27, 2017 (Thu) 4:00 pm  Seminar Room(#1323, E6-2)  Prof.Donghan Lee (Chungnam National Univ.)  반도체 양자점을 이용한 단광자 광원
294 2017/03/06 - 05/29  Seminar Room 1501  이종봉 박사 (POSTECH) 외  Spring 2017: Physics Colloquium file
293 2017/03/21 - 06/08  Seminar Room 1323  조길영 박사(KAIST) 외  Spring 2017: Physics Seminar Serises file
292 Thursday, December 14, 2017 at 3:00 pm  Seminar Room (C303), Creation Hall (3F), KAIST Munji Campus  Chunglee Kim (KASI)  Exploring the Universe via GWs in the era of multi-messenger astronomy
291 July 2. 2018 (Monday) 3:00 PM  Seminar Room (C303), Creation Hall (3F), KAIST Munji Campus  Dr. Peter Winter (Argonne National Laboratory)  High Precision Magnetic Field Measurement for the Muon g-2 Experiment file
290 Jun. 14 (Tue) 4PM  Seminar Room (#2502, 2nd fl.)  Young-Sik Ra, Université Pierre et Marie Curie  Photonic quantum network based on multimode squeezed vacuums and single-photon subtraction
289 Nov. 1 (Tue.) 2:30 pm  Seminar Room #1323(E6-2)  Prof. Youngjoon Kwon, Yonsei Univ.  Search for dark sector particles in the B-factory experiments