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VERSION:2.0
PRODID:icalendar-ruby
CALSCALE:GREGORIAN
X-WR-CALNAME:Physics Colloquium: Igor Barsukov\, University of California\,
  Riverside
X-WR-TIMEZONE:Eastern Time (US & Canada)
BEGIN:VEVENT
DTSTAMP:20261018T035845Z
UID:tag:localist.com\,2008:EventInstance_40906554026655
DTSTART:20221102T200000Z
DTEND:20221102T210000Z
DESCRIPTION:Interplay of spin-torque and nonlinearity:\nDisentangling and c
 ontrolling magnon processes in nanomagnets\n\nNanoscale magnets are the bu
 ilding blocks of various spintronics technologies. However\, many aspects 
 of spin dynamics in the nanoscale geometrical confinement have remained el
 usive. For instance\, untangling damping contributions and engineering res
 ponse of nanomagnets to external drives is a challenging task. \nUsing mag
 netic tunnel junctions – the flagship technology of spintronics industry
  – as a sample platform\, we investigate the discrete magnon spectrum of
  individual zero-dimensional magnets and identify the inherent inter-magno
 n processes. While manipulation of magnetization by spin-torque\, i.e. by 
 influx of angular momentum\, is a key functionality of today’s spintroni
 cs\, we find that resonant magnon processes redefine and invert nanomagnet
 ’s response to spin-torque [1]. We discuss the mechanisms of this counte
 r-intuitive interplay of nonlinearity and angular momentum flows\, which h
 as far-reaching implications for the performance of magnetic memory and os
 cillators.\nControlling magnon processes and thus forging the nonlinearity
  of a nanomagnet would add decisive functionality to existing and emerging
  technologies\, in particular to magnetic neuromorphic networks where tuna
 bility of the nonlinear response is instrumental. We develop an approach f
 or engineering magnon interaction by means of symmetry-breaking fields wit
 h nanoscale nonuniformity [2]. In a proof-of-concept\, we employ a nanosca
 le auxiliary element (a synthetic antiferromagnet) as a switchable source 
 of such fields and achieve tunability of magnon coupling by at least one o
 rder of magnitude. The results open up avenues for controlling magnon proc
 esses by external stimuli at nanoscale and show prospects for spin-torque 
 applications\, magnetic neuromorphic systems\, and emergent hybrid quantum
  information technologies.\n\nThis work was supported by the National Scie
 nce Foundation through Grant No. ECCS-1810541 and by NVidia Corp. \n\nRefe
 rences\n1. Giant nonlinear damping in nanoscale ferromagnets\, I. Barsukov
  et al.\, Sci. Adv. 5\, eaav6943 (2019)\,   http://dx.doi.org/10.1126/scia
 dv.aav6943\n2. Controlling magnon interaction by a nanoscale switch\, A. E
 tesamirad et al.\, ACS Appl. Mater. Interfaces 13\, 20288 (2021)\, https:/
 /doi.org/10.1021/acsami.1c01562
GEO:42.335064;-71.168846
LOCATION:Higgins Hall\, 310
SUMMARY:Physics Colloquium: Igor Barsukov\, University of California\, Rive
 rside
URL;VALUE=URI:https://events.bc.edu/event/physics_colloquium_igor_barkusov_
 university_of_california_riverside
CATEGORIES:Lecture
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