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
332 March 18(Fri.) 11:00  Online seminar  Dr. Dirk Wulferding (IBS-Center for Correlated Electron Systems, Seoul National University, Seoul)  (응집물리 세미나) Illuminating exotic states of matter: Raman spectroscopy as an experimental tool to characterize quantum spin liquids file
331 April 15(Fri.) 11:00  Online seminar  Prof.Jaekwang Lee (Department of Physics, Pusan National University)  (응집물리 세미나) First-principles studies of polar oxides and their applications file
330 June 3rd, Fri. 9:30 AM  Online seminar  Prof. Juejun Hu ( Massachusetts Institute of Technology)  (Quantum-&Nano-Photonics Webinar) Seeing glass in a new light: reimagine chalcogenide photonics file
329 Jun. 10 (Fri.), 11:00 AM  Online seminar  Dr. Yoon Jang Chung(Laboratory for Physical Sciences, University of Maryland)  Record-quality two-dimensional electron systems file
328 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
327 Jan.28(Thu), 06:00PM  Online Seminar  Alexandre Zagoskin(Loughborough Univ.)  Quantum metamaterials: concept, theory, prototypes and possible applications file
326 7월 29일(목) 오후 2시 ~ 오후 4시  Online seminar  Dr. Kunio Kaneta(KIAS)  Gravitationally Induced Dark Sector and Inflationary Dynamics file
325 Jun. 11 (Fri.), 02:30 PM  Online seminar  Dr. Jin Woong Cha(KRISS)  Engineering sound waves and vibrations in multi-mode nanomechanical systems file
324 Jun. 11 (Fri.), 04:00 PM  Online seminar  Dr. Keun Su Kim(Yonsei University)  Pseudogap in surface-doped black phosphorus file
323 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
322 4pm, 31th March  online  최현용 (서울대학교 물리천문학부)  (광학분야 특별세미나)Ultrafast time-resolved spectroscopy in topological materials
321 3pm, 19th May  online  Jonghee Yoon, PhD (Assistant professor, Department of Physics, Ajou University)  (광학분야 특별세미나)Development of a multimodal optical system for improved disease diagnosis
320 3pm, 19th May  online  Jonghee Yoon, PhD (Assistant professor, Department of Physics, Ajou University)  (광학분야 특별세미나)Development of a multimodal optical system for improved disease diagnosis
319 Nov. 20 (Fri.), 02:30 PM  Online  Dr. Doohee Cho  Lumpy Cooper pairs in an iron-based superconductor
318 Mar 2 (Tue.), 16:00  Online  Dr. Dmitry Svintsov  Sensitive terahertz detection with graphene-based transistors file
317 Dec. 11 (Fri.), 04:00 PM  online  Hyobin Yoo(Sogang Univ.)  Atomic and electronic reconstruction at van der Waals interface in twisted 2D materials
316 Dec. 11 (Fri.), 02:30 PM  online  Myung Hwa Jung(Sogang Univ.)  Antisymmetric interlayer exchange coupling in magnetic multilayers
315 Dec.23(Wed), 10:00~16:00  Online  Prof. YongKeun Park (KAIST) and etc.  Online workshop for Quantitative Phase Imaging file
314 Nov. 20 (Fri.), 04:00 PM  Online  Dr. Dohun Kim  Coherent control of field gradient induced quantum dot spin qubits
313 Feb.17(Wed)~19(Fri), 09:00~11:00AM  Online  Prof. Subir Sachdev (Harvard University)  석학 대중 강연 및 강의 시리즈 file