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 |
---|---|---|---|---|
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 |
275 | Jul. 07 (Thu.) 2PM | #1323(E6-2. 1st fl.) | Dr. Eun Ah Kim, CORNELL UNIV. | Let there be topological superconductors |
274 | Sep. 22 (Fri.), 01:00 PM | E6-2. 1st fl. #1323 | Dr. EunSeong Kim / Department of Physics, KAIST |
Superconductor-metal-insulator transition in thin Tantalum films
![]() |
273 | Jun. 2 (Fri.), 02:30 PM | E6-2. 1st fl. #1323 | Dr. Euyheon Hwang(황의헌) |
Quasiparticle Interference and Fourier transform scanning tunneling spectroscopy in WTe2 (Weyl semimetal)
![]() |
272 | May 24 (Tue) 4 PM | E6-2. #1323(1st fl.) | Dr. Euyheon Hwang, SKKU Advanced Institute of Nanotechnology, Sung Kyung Kwan University | Electronic and magnetic properties of 2D transition-metal thiophosphates and tunability of magnetic order with carrier density |
271 | April 4, 2016 (Mon) - April 8, 2016 (Fri) | KAIST Natural Science Building (E6-2), RM #4314 | Dr. Fritz Caspers (CERN) | Radio frequency engineering |
270 | Nov. 1st (Tue), 10:30AM | #1323(E6-2 1st fl.) | Dr. Gadi Eisenstein, Technion | Time scale dependent dynamics in InAs/InP quantum dot gain media |
269 | October 25 (Thu.), 4:00 PM | #1323, E6-2 | Dr. Gang Li |
Abelian and non-Abelian dark photons
![]() |
268 | Sep. 22 (Fri.), 02:30 PM | E6-2. 1st fl. #1323 | Dr. GilHo Lee / Department of Physics, POSTECH |
Quantum Electronic Transport in Graphene Hybrid Nanostructures
![]() |
267 | Sep. 22 (Fri.), 04:00 PM | E6-2. 1st fl. #1323 | Dr. GilHo Lee / Department of Physics, POSTECH |
Unexpected Electron-Pairing in Integer Quantum Hall Effect
![]() |
266 | Dec. 7 (Fri.), 02:30 PM | E6-2. 1st fl. #1323 | Dr. Gyung Min Choi |
Spin generation from heat and light in metals
![]() |
265 | 2015/09/14, 2PM | E6-2. 2nd fl. #2501 | Dr. Hae Ja Lee ( Stanford University, SLAC ) | Ultrafast X-ray Studies on Dynamics Matter in Extreme Conditions |
264 | Sep. 22, 2016(Thu), 3:30 PM | #1323(E6-2, 1st fl.) | Dr. Haiyang Yan (Institute of Nuclear Physics and Chemistry) | Polarized 3He, Polarized Neutrons and New Interactions beyond the Standard Model |
263 | Sep. 22, 2016(Thu), 3:30 PM | #1323(E6-2, 1st fl.) | Dr. Haiyang Yan (Institute of Nuclear Physics and Chemistry) | Polarized 3He, Polarized Neutrons and New Interactions beyond the Standard Model |
262 | May 19 (Thu) 4PM | #1323(E6-2, 1st fl.) | Dr. Heedeuk Shin, POSTECH | Nonlinear/quantum optical effect in silicon nano-photonics |
261 | 2015/10/23, 3PM | E6-2, #5318 | Dr. Helmut Soltner (Forschungszentrum Juelich) | Development of a Rogowski Coil as a new beam position monitor |
260 | Jun 24 (Mon) 11:00 | E6-2, #1323 | Dr. Henning Schomerus |
Topological photonic anomalies
![]() |
» | 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 |
258 | Jan.9 (Wed.), 04:00 PM | E6-2. 2nd fl. #2501 | Dr. Heung-Sik Kim |
Molecular Mott state in the deficient spinel GaV4S8
![]() |
257 | Nov. 16 (Wed), 4p.m. | #1323(E6-2. 1st fl.) | Dr. Heung-Sik Kim , University of Toronto | Realizing Haldane Model in Fe-based Honeycomb Ferromagnetic Insulators |
256 | May 13 (Fri.) 4 PM | E6. #1501(1st fl.) | Dr. Hosub Jin, Dept. of Physics, UNIST | Graphene analogue in (111)- BaBiO3 bilayer heterostructures for topological electronics |