Entanglement probe of two-impurity Kondo physics
2016.09.19 16:01
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)
댓글 0
번호 | 일시 | 장소 | 연사 | 제목 |
---|---|---|---|---|
312 | 4. 11(월),16:00 | E6, #1501 | 노재동교수 (서울시립대 물리학과) | Emergence of Statistical Mechanics in Quantum Systems |
311 | 4. 25(월), 16:00 | E6, #1501 | 정영욱 책임연구원 (한국원자력연구원) | Ultrafast electron beam, a tool to explore the nanoscopic world of materials(우리말강의) |
310 | 4. 4(월), 16:00 | E6, #1501 | 김희철교수 (Postech 물리학과) | New paradigms in Quantum Field Theory |
309 | 4pm, 10th May | E6 1323 | 권혁준 (Korea Institute for Advanced Study, KIAS) | (광학분야 특별세미나)Testing quantum thermodynamics using quantum optics |
308 | 4pm, 14th April | E6 1323 | 신승우 (KAIST 물리학과) | (광학분야 특별세미나)Holographic tomography of dielectric tensors at optical frequency |
307 | 4pm, 26th May | E6 1323 | 황민수 (Department of Physics, Korea University) | (광학분야 특별세미나)Topological photonic devices |
306 | 4pm, 28th April | E6 1323 | 유경식 (KAIST 전기및전자공학부) | (광학분야 특별세미나)Adiabaticity and symmetry in optical waveguide design |
305 | 4pm, 31th March | online | 최현용 (서울대학교 물리천문학부) | (광학분야 특별세미나)Ultrafast time-resolved spectroscopy in topological materials |
» | 4pm, Sep. 21 (Wed. | E6-2. #2502(2nd fl.) | Dr. Henrik Johannesson , University of Gothenburg (Sweden) and Beijing Computational Science Research Center (China) | Entanglement probe of two-impurity Kondo physics |
303 | 4월 18일(월), 15:30~ | KI빌딩(E4), 강의실 B501 (5F) | Prof. Robert A. DiStasio Jr. (Cornell University) |
First Principles Approaches for Intermolecular Interactions: From Gas-Phase Dimers to Liquid Water and Molecular Crystal Polymorphism
![]() |
302 | 5. 2(월),16:00 | E6, #1501 | 유상운교수 (한밭대) | What can we learn from the history of science and technology?(우리말강의) |
301 | 5. 23(월),16:00 | E6, #1501 | 김준성교수 (postech 물리학과) | Novel electronic transport in topological van der Waals magnets |
300 | 5. 30(월), 16:00 | E6, #1501 | 공수현교수 (고려대학교 물리학과) | Light manipulation using 2D layered semiconductors |
299 | 5. 9(월),16:00 | E6, #1501 | 김창영교수 (서울대) | Searching for new electronic properties in correlated material flatland |
298 | 5.16(월),16:00 | E6, #1501 | 조규붕교수 (HKUST) | Design synthetic topological matter with atoms and lights |
297 | 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 |
296 | 5월27일(목) 오후4시 | 온라인 | 박소현 박사(CERN) / 이혜성 교수(KAIST) |
찾아가는 물리연구 현장(유럽 입자물리학연구소 소개)
![]() |
295 | 7월 29일(목) 오후 2시 ~ 오후 4시 | Online seminar | Dr. Kunio Kaneta(KIAS) |
Gravitationally Induced Dark Sector and Inflationary Dynamics
![]() |
294 | 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
![]() |
293 | Apr. 01 (Fri.) 2:30 PM | E6-2. 1st fl. #1501 | Dr. KICHEON KANG, Chonnam National University | Interference of single charged particles without a loop and dynamic nonlocality |