visual
visual

세미나

  • HOME
  • >
  • 소식
  • >
  • 세미나
날짜 2024-06-13 16:00 
일시 June 13th(Thur), 16:00 
장소 E6-2, #1323 
연사 Dr. Kouki Nakata (Japan Atomic Energy Agency) 
Dr. Kouki Nakata (Advanced Science Research Center, Japan Atomic Energy Agency)를 모시고 'Magnonic $\varphi$ Josephson junction and its non-Hermitian Josephson diode effect' 주제에 대한 세미나를 개최하고자 합니다. 
물리학과 구성원 여러분들의 많은 참여 부탁드립니다.
--------------------------------------------------------------------------------------------------------------------
1) Time : at 16:00 on Jun 13, 2024
2) Venue : E6-2, Rm#1323
3) Speaker : Dr. Kouki Nakata (Advanced Science Research Center, Japan Atomic Energy Agency)
4) Talk Title : Magnonic $\varphi$ Josephson junction and its non-Hermitian Josephson diode effect
5) Abstract
   - There has been a growing interest in non-Hermitian physics [1]. One of its main goals is to engineer dissipation and to explore ensuing functionality. Since magnons are intrinsically damped in magnets, its dynamics aligns well with the goal of non-Hermitian physics [2]. Although the effect of dissipation due to local damping on magnon transport has been explored, the effects of non-local damping on the magnonic analog of the Josephson effect [3] remain missing, despite that non-local damping is inevitable in magnets. Here, we uncover theoretically that rich dynamics can emerge in magnetic junctions due to intrinsic non-local damping, using analytical and numerical methods [4]. In particular, under microwave pumping, we show that coherent spin precession in the right and left insulating ferromagnet (FM) of the junction becomes synchronized by non-local damping and thereby a magnonic analog of the $\varphi$ Josephson junction emerges, where $\varphi$ stands here for the relative precession phase of right and left FM in the stationary limit. Remarkably, $\varphi$ decreases monotonically from $ \pi$ to $\pi/2$ as the magnon-magnon interaction increases. Moreover, we also find a magnonic Josephson diode effect giving rise to rectification of magnon currents. Our predictions are readily testable with current device and measurement technologies.
 
 
[1] Y. Ashida, Z. Gong, and M. Ueda, Adv. Phys. 69, 249 (2020).
[2] T. Yu, J. Zou, B. Zeng, J. Rao, and K. Xia, Phys. Rep. 1062, 1 (2024); J. Zou, S. Bosco, E. Thingstad, J. Klinovaja, and D. Loss, Phys. Rev. Lett. 132, 036701 (2024).
[3] KN, K. A. van Hoogdalem, P. Simon, and D. Loss, Phys. Rev. B 90, 144419 (2014); H. Katsura, N. Nagaosa, and A. V. Balatsky, Phys. Rev. Lett. 95, 057205 (2005).
[4] KN, J. Zou, J. Klinovaja, D. Loss, arXiv:2403.01625 (2024); references therein.
번호 날짜 장소 제목
168 2019-09-10 15:00  E6-2. 1st fl. #1323  Two-Stage Kondo Effect file
167 2017-02-01 14:00  #1323(E6-2. 1st fl.)  Quantum electron optics using flying electrons
166 2015-11-23 13:30  E6-2, #1323  What's Beyond the Standard Model? Lessons from Run I and what might come in Run II
165 2016-07-08 11:00  #1323(E6-2. 1st fl.)  Isostatic magnetism
164 2016-05-19 15:00  May 19, 2016 (Thur.) 3PM,  The CERN Resonant WISP Search: Development, Results and Lesson-Learned
163 2023-06-22 16:00  CAPP Seminar Room C303, Creation Hall, KAIST Munji Campus  [CAPP Seminar] The muon g-2 puzzle file
162 2015-10-15 10:00  E6-2, 5th fl. #5318  Development of Large-Bore, High Field Magnets at the NHMFL
161 2017-03-24 14:30  #1323 (1st fl. E6-2).  Topological Dynamics
160 2018-10-26 16:00  #1323, E6-2  Coexisting triple-point and nodal-line topological magnons and thermal Hall effect in pyrochlore iridates file
159 2015-07-16 16:00  E6-2, 1318  Next-generation ultrafast laser technology for nonlinear optics and strong-field physics
158 2023-04-27 11:00  E6-2 #1322  Inverse Shapiro steps and coherent quantum phase slip in superconducting nanowires
157 2022-08-18 10:00  E6-1 #1323  Disorder-driven phase transition in the second-order non-Hermitian skin effect
156 2018-11-01 16:00  #1323, E6-2  Direct holography from a single snapshot file
155 2016-03-11 13:30  E6-2. 1st fl. #1501  Topological phases of matter in nonequilibrium: Topology of the Wannier-Stark ladder
154 2015-12-11 13:30  E6-2, #1323  Quantum spin liquid in the 1/3 depleted triangular lattice Ba3(Ru1-xIrx)Ti2O9
153 2021-07-29 14:00  Online seminar  Gravitationally Induced Dark Sector and Inflationary Dynamics file
152 2022-05-13 14:30  Zoom webinar  Topological Superconducting Spintronics Towards Zero-Power Computing Technologies file
151 2016-12-09 16:00  #1323(E6-2. 1st fl.  Shift Charge and Spin Photocurrents in Dirac Surface States of Topological Insulator
150 2018-05-11 14:30  E6-2. 1st fl. #1323  Disordered Floquet topological insulators file
149 2023-09-14 16:00  CAPP Seminar Room C303, Creation Hall, KAIST Munji Campus  [CAPP seminar] Dark matter searches in Water Cherenkov Detectors file