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 1060297
102 학술세미나 개최 안내: Local Modes in Vibrational (and Rotational) Spectroscopy file 2015.10.01 55719
» <8/5(Fri.) 10:30> Phase Slips in Superfluid Spin Transport in Magnetic Wires 2016.08.02 55708
100 <March. 9(Wed.) 4:30 PM>가치 있는 대학 생활이란 무엇인가? file 2016.03.07 55674
99 <8/26(Mon) 14:00 ~ >Constructing viable models of bouncing scenarios 2019.08.20 55673
98 <May 10(Wed.) 4:30 PM>Trend and beyond of semiconductor technology (반도체 미세화 및 신기술 동향) 2017.05.04 55647
97 <Dec.13(Wed.) 4:30 PM>기본에 충실하고 새로움에 도전한다 - 자율주행자동차의 핵심 기술들 – 2017.12.07 54848
96 <Nov. 2(Wed.) 4:30 PM> 현대 우주론 이론과 관찰 (Theories and observations of modern cosmology) 2016.10.19 54818
95 <12/2(Fri.) 14:00>Overview of HIMAC facility 2016.12.01 54720
94 <June 8(Wed.) 4:30 PM> 세계와 우리나라 우주개발 도전 2016.06.01 54642
93 <Mar.20(Wed.)> Connecting Thermoelectricity and Superconductivity by Pressure Bridge 2019.03.13 54610
92 <April. 27(Wed.) 4:30 PM> 로봇과 함께 살아갈 미래 2016.04.22 54228
91 <May. 4(Wed.) 4:30 PM> 플라즈마를 이용한 표면처리 기술 2016.04.27 54155
90 <Dec. 14(Wed.) 4:30 PM>중력과 양자 얽힘 (tentative) 2016.12.07 53888
89 <Mar. 15(Wed.) 4:30 PM>반도체 Fab Process와 물리학 전공자 2017.03.14 53877
88 <Nov. 9(Wed.) 4:30 PM> 20-nm resolution imaging of brain circuitry by next-generation expansion microscopy 2016.11.02 53855
87 <May. 18(Wed.) 4:30 PM> Search for Hidden Neutrinos at the High Energy Frontier 2016.05.23 53837
86 <8/23(Thu.) 2:00pm>What will we do with near-term quantum computers? 2018.08.17 53656
85 <June 1(Wed.) 4:30 PM> 중력으로 강한 핵력 이해하기 2016.05.26 53537
84 <11/21(Wed.) 2:00pm>Origin of Hawking Radiation 2018.11.20 53376
83 <April 25(Mon) 16:30> Neutron Recoil Polarization in Low‐energy Photodisintegration of the Deuteron 2016.04.25 53259