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
298 Feb. 25 - Jun 3  Rm. 1501 (E6)    Spring 2019: Physics Colloquium file
297 RM. 1323, E6-2    Spring 2019: Physics Seminar Serises file
296 August 27 (Tue.), 4:00PM  Rm. 1323, E6  Hiroshi Eisaki  Critical current properties of Fe-based superconductors file
295 August. 14th (Wed.), 4:00PM,  Rm. 1323, E6  Prof. Nicolas Treps  Quantum Optics, at the heart of quantum metrology and quantum information file
294 2019. 7. 16(화)  Rm. 1323 (E6-2)  Prof. Sidney Nagel  2019 Physics Distinguished Lecture file
293 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
292 3 PM, 12 Jun (Wed), 2019  Rm# 1323, E6-2  Dr. Minyoung You  The relation between free and interacting fermionic SPT phases file
291 Apr. 2 (Fri.), 04:00 PM  Online(Zoom)  Dr. Heejun Yang (KAIST)  Van der Waals heterostructures for orbital gating-based phototransistors and electronic spectroscopy
290 Apr. 2 (Fri.), 02:30 PM  Online(Zoom)  Dr. Tae Hyun Kim (SNU)  Quantum computing and entanglement generation using trapped ions and photons
289 Nov.26(Thu), 04:00PM  Online(Zoom)  Myung-Ki Kim  2020 가을학기 광학분야 특별세미나(Light Engineering Beyond the Diffraction Limit)
288 Nov 17th 12:00 PM  Online(Zoom)  Prof. Qiang Lin (Univ. of Rochester, USA)  Quantum- & Nano-Photonics" 세미나 시리즈 file
287 Mar25(Thur), 04:00PM  Online Seminar (Zoom)  Prof. Atsushi Tokiyasu (Tohoku Univ.)  Search for dark matter axion with Rydberg atoms file
286 Jun. 11 (Fri.), 04:00 PM  Online seminar  Dr. Keun Su Kim(Yonsei University)  Pseudogap in surface-doped black phosphorus file
285 Jun. 11 (Fri.), 02:30 PM  Online seminar  Dr. Jin Woong Cha(KRISS)  Engineering sound waves and vibrations in multi-mode nanomechanical systems file
284 May. 14 (Fri.), 02:30 PM  Online seminar  Dr. Suyong Jung(KRISS)  Electrically tunable spin valve effect in vertical van-der-Waals magnetic tunnel junctions file
283 May. 14 (Fri.), 04:00 PM  Online seminar  Dr. Je-Hyung Kim(UNIST)  Spatial and temporal separation of environmental dephasing sources from solid-state quantum emitters file
282 Jan.28(Thu), 06:00PM  Online Seminar  Alexandre Zagoskin(Loughborough Univ.)  Quantum metamaterials: concept, theory, prototypes and possible applications file
281 Mar 2 (Tue.), 16:00  Online  Dr. Dmitry Svintsov  Sensitive terahertz detection with graphene-based transistors file
280 Feb.17(Wed)~19(Fri), 09:00~11:00AM  Online  Prof. Subir Sachdev (Harvard University)  석학 대중 강연 및 강의 시리즈 file
279 Dec.23(Wed), 10:00~16:00  Online  Prof. YongKeun Park (KAIST) and etc.  Online workshop for Quantitative Phase Imaging file