korean english


Home > 게시판 > 세미나

일시: 8월 5일(금) 오전 10:30 ~ 12:00

장소: 31동 2층 물리학과 라운지세미나실

연사: 김  세  권 박사님 (UCLA)

Title: Phase Slips in Superfluid Spin Transport in Magnetic Wires

○ Abstract:

In this talk, we will discuss two types of mechanisms responsible for intrinsic resistance in superfluid spin transport in easy-plane magnetic wires: thermally-activated and quantum phase slips. First, we theoretically study thermally-activated phase slips within the stochastic Landau-Lifshitz-Gilbert phenomenology, which runs parallel to the Langer-Ambegaokar-McCumber-Halperin theory for thermal resistances in superconducting wires [1]. To that end, we start by obtaining the exact solutions for free-energy minima and saddle points. We provide an analytical expression for the phase-slip rate in the zero spin-current limit, which involves detailed analysis of spin fluctuations at extrema of the free energy. 

Secondly, we theoretically investigate effects of quantum fluctuations on superfluid spin transport through easy-plane quantum antiferromagnetic spin chains in the large-spin limit [2]. Quantum fluctuations result in the decaying spin supercurrent by unwinding the magnetic order parameter within the easy plane, which is referred to as phase slips. We show that the topological term in the nonlinear sigma model for the spin chains qualitatively differentiates decaying rate of the spin supercurrent between integer and half-odd-integer spin chains. We propose an experimental setup for a magnetoelectric circuit, in which both phase slips can be inferred by measuring nonlocal magnetoresistance.

[1] S. K. Kim, S. Takei, and Y. Tserkovnyak, Phys. Rev. B \textbf{93}, 020402(R) (2016)

[2] S. K. Kim and Y. Tserkovnyak, Phys. Rev. Lett. \textbf{116}, 127201 (2016)

번호 제목 날짜 조회 수
공지 <12/8(Thu.) 11:00am>노벨상 소개 강연 - 2016년 노벨 물리학상: 위상 응집 물리의 탄생 2016.11.28 1079595
487 <10/10>Self-reconfigurable robots 2008.10.07 97354
486 <6/5> BK 석학초청 특별강연 - How Well Does High Field Specific Heat Probe the Nodal Nature of the Multi- 2012.05.14 97350
485 <4/10> Mapulation of spins in organic compounds 2013.04.03 96949
484 <10/22(Tue.)>To p or not to p? – 17O NMR of Sr2RuO4 under strain file 2019.10.17 96593
483 2016학년도 2학기 콜로퀴움 일정 2016.08.02 96515
482 2007학년도 2학기 콜로키엄 schedule 안내 2007.09.27 96475
481 <7월27일>Correlated topological phases in 3D complex oxides via Green's functions 2012.07.27 96323
480 <3/9> Understanding the Nature of Metal-Insulator Transition in a Single Crystalline VO2 nanowires 2011.03.04 96162
479 <4/22> How Many is Different? Ideal Bose gas revisited 2011.04.22 96141
478 <12/14> Breakup-Fusion and Knockout-Fusion Approach to Pre-Equilibrium Processes 2009.12.11 96110
477 <12/10(Tue.)> Investigating dark matter signals at neutrino telescopes 2019.12.06 95898
476 <May.16(Wed.) 4:30 PM> Single crystal growth of metal film and metal oxide film on different substrates and their various applications 2018.05.09 95666
475 <11/21> 복잡 산화물 이종접합 및 다강체 연구(Complex oxide heterostructures and multiferroics) 2012.11.15 95635
474 <1/26> Hamiltonian formalism 2011.01.19 95348
473 <9/8>Dynamics of one-dimensional electrons and exotic elementary excitations 2006.09.04 95310
472 <Nov.18(Wed.)>When Physics meets the Living Cells 2020.11.11 95102
471 <9/18> 생체계에서의 협동현상: 박테리아 수영에서부터 고분자 수송현상까지 2009.09.14 94880
470 <4/17> Probing Stellar Explosions with Radioactive Beams* 2013.04.10 94703
469 <5/14> Synthesis of Two Dimensional Materials by Chemical vapor deposition 2014.05.07 94591
468 <6/12> Latest Results from the IceCube Neutrino Observatory 2013.06.07 94433