BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//CERN//INDICO//EN
BEGIN:VEVENT
SUMMARY:Magnons as uncharged carriers for quantum communication between na
 nomagnets
DTSTART;VALUE=DATE-TIME:20260923T142000Z
DTEND;VALUE=DATE-TIME:20260923T144000Z
DTSTAMP;VALUE=DATE-TIME:20260914T070158Z
UID:indico-contribution-524@indico.bitp.kiev.ua
DESCRIPTION:Speakers: Serhii Tunyk (Bogolyubov Institute for Theoretical P
 hysics\, National Academy of Sciences of Ukraine)\nRecent experimental stu
 dies have shown that magnonics—an independent branch of spintronics—ca
 n realize its potential in nanotechnology applications involving magnetoph
 otonics\, thermal nanoconversion\, magnonic capacitors\, magnonic transist
 ors\, and other fields. Magnons are very good candidates for use in quantu
 m communication. This is because the transport of magnons as uncharged qua
 siparticles can occur without the generation of Joule heat\, and\, just as
  with charged carriers\, this transport can be controlled using magnetic a
 nd electric fields. We propose a physical mechanism whereby a localized sp
 in excitation (Kittel magnon) generated in one microwave cavity can be res
 onantly transferred to another cavity via a ferromagnetic chain connecting
  the nanomagnets embedded in the cavities. It is shown that long-range mag
 non transfer can be achieved via coherent one-step tunneling of magnons be
 tween nanomagnets. Our theoretical study is based on a model in which\, fo
 r fixed nanomagnet spin values\, the states are determined by macrospin pr
 ojections\, and the ferromagnetic chain acts as a mediating scattering cen
 ter. The coupling between spin excitations in the "nanomagnet A - ferromag
 netic chain - nanomagnet B" hybrid structure (AFB structure) is mediated b
 y the Heisenberg exchange interaction between the spins of adjacent parama
 gnetic units of the structure. Based on this model\, analytical formulas w
 ere derived that made it possible to understand the physics of controlling
  magnon flow using magnetic fields\; these fields tune the Kittel magnon f
 requency to the frequencies of delocalized magnons in the AFB structure. T
 he main results of the study include the following. Analytical expressions
  for the magnon transport rate and magnon flow are obtained and key parame
 ters controlling off-resonant and resonant magnon tunneling regimes are in
 dicated. Physical conditions are determined under which peak values of the
  rate characterizing the process of resonant transmission of the Kittel ma
 gnon arise both at a fixed tunneling energy with an arbitrary number of un
 its in the ferromagnetic chain or at a fixed number of chain units with a 
 changing tunneling energy. A mechanism of coherent transfer is proposed\, 
 based on the premise that the spin states of a bridge\, containing magneti
 cally ordered paramagnetic units\, play a virtual role. This facilitates a
  specific quantum exchange of magnons both within the bridge and between i
 ts terminal units and the adjacent nanomagnets. As a result\, a long-range
  superexchange coupling arises between magnetostatic spin excitations\, wh
 ich ensures a tunnel regime of magnon transport between nanomagnets. It wa
 s also shown that due to the strong photon-magnon coupling in the microwav
 e  cavity\, at a certain magnetic field\, the tunneling flow of magnons ca
 n reach an additional peak value\, which reflects the process of resonant 
 photon-to-magnon conversion [1]. The obtained results indicate the potenti
 al for using magnons for quantum communication in hybrid structures where 
 the transduction of one type of quasiparticle into another (in our case\, 
 photons and magnons) is possible.\n\nThis work is partialy supported by th
 e project of the Ministry of Education and Science of Ukraine «Developmen
 t of theoretical and computational methods for the study of micro- and mac
 rosystems in quantum technology”\n\n[1] E. G. Petrov\, S. M. Tunyk\, V.V
 . Gorbach\, Phys. Rev. Appl.\, 25\, 024072 (2026).\n\nhttps://indico.bitp.
 kiev.ua/event/18/contributions/524/
LOCATION:Bogolyubov Institute for Theoretical Physics Conference Hall
URL:https://indico.bitp.kiev.ua/event/18/contributions/524/
END:VEVENT
END:VCALENDAR