• Angle Resolved Relaxation of Spin Currents by Antiferromagnets in Spin Valves 

      Polishchuk, Dmytro; Kamra, Akashdeep; Polek, Taras; Brataas, Arne; Korenivski, Vladislav (Peer reviewed; Journal article, 2019)
      We observe and analyze tunable relaxation of a pure spin current by an antiferromagnet in spin valves. This is achieved by carefully controlling the angle between a resonantly excited ferromagnetic layer pumping the spin ...
    • Anisotropic and controllable Gilbert-Bloch dissipation in spin valves 

      Kamra, Akashdeep; Polishchuk, Dmytro; Korenivski, Vladislav; Brataas, Arne (Peer reviewed; Journal article, 2019)
      Spin valves form a key building block in a wide range of spintronic concepts and devices from magnetoresistive read heads to spin-transfer-torque oscillators. We elucidate the dependence of the magnetic damping in the free ...
    • Antiferromagnetic magnons as highly squeezed Fock states underlying quantum correlations 

      Kamra, Akashdeep; Thingstad, Even; Rastelli, Gianluca; Duine, Rembert A.; Brataas, Arne; Belzig, Wolfgang; Sudbø, Asle (Peer reviewed; Journal article, 2019)
      Employing the concept of two-mode squeezed states from quantum optics, we demonstrate a revealing physical picture for the antiferromagnetic ground state and excitations. Superimposed on a Néel ordered configuration, a ...
    • Chiral Phonon Transport Induced by Topological Magnons 

      Thingstad, Even; Kamra, Akashdeep; Brataas, Arne; Sudbø, Asle (Peer reviewed; Journal article, 2019)
      The plethora of recent discoveries in the field of topological electronic insulators has inspired a search for boson systems with similar properties. There are predictions that ferromagnets on a two-dimensional honeycomb ...
    • Enhancement of superconductivity mediated by antiferromagnetic squeezed magnons 

      Erlandsen, Eirik; Kamra, Akashdeep; Brataas, Arne; Sudbø, Asle (Journal article; Peer reviewed, 2019)
      We theoretically investigate magnon-mediated superconductivity in a heterostructure consisting of a normal metal and a two-sublattice antiferromagnetic insulator. The attractive electron-electron pairing interaction is ...
    • Exchange-enhanced ultrastrong magnon-magnon coupling in a compensated ferrimagnet 

      Liensberger, Lukas; Kamra, Akashdeep; Maier-Flaig, Hannes; Gepraegs, Stephan; Erb, Andreas; Goennenwein, Sebastian; Gross, Rudolf; Belzig, Wolfgang; Huebl, Hans; Weiler, Mathias (Peer reviewed; Journal article, 2019)
      We experimentally study the spin dynamics in a gadolinium iron garnet single crystal using broadband ferromagnetic resonance. Close to the ferrimagnetic compensation temperature, we observe ultrastrong coupling of clockwise ...
    • Magnon decay theory of Gilbert damping in metallic antiferromagnets 

      Simensen, Haakon Thømt; Kamra, Akashdeep; Troncoso, Roberto; Brataas, Arne (Peer reviewed; Journal article, 2020)
      Gilbert damping is a key property governing magnetization dynamics in ordered magnets. We present a theoretical study of intrinsic Gilbert damping induced by magnon decay in antiferromagnetic metals through s−d exchange ...
    • Magnon-Mediated Indirect Exciton Condensation through Antiferromagnetic Insulators 

      Johansen, Øyvind; Kamra, Akashdeep; Ulloa, Camilo; Brataas, Arne; Duine, Rembert (Journal article; Peer reviewed, 2019)
      Electrons and holes residing on the opposing sides of an insulating barrier and experiencing an attractive Coulomb interaction can spontaneously form a coherent state known as an indirect exciton condensate. We study a ...
    • Magnon-polarons in cubic collinear antiferromagnets 

      Simensen, Haakon Thømt; Troncoso, Roberto; Kamra, Akashdeep; Brataas, Arne (Peer reviewed; Journal article, 2019)
      We present a theoretical study of excitations formed by hybridization between magnons and phonons—magnon-polarons—in antiferromagnets. We first outline a general approach to determining which magnon and phonon modes can ...
    • Phonon-mediated superconductivity in doped monolayer materials 

      Thingstad, Even; Kamra, Akashdeep; Wells, Justin; Sudbø, Asle (Peer reviewed; Journal article, 2020)
      Insight into why superconductivity in pristine and doped monolayer graphene seems strongly suppressed has been central for the recent years' various creative approaches to realize superconductivity in graphene and graphene-like ...
    • Spin current cross-correlations as a probe of magnon coherence 

      Bender, Scott A.; Kamra, Akashdeep; Belzig, Wolfgang; Duine, Rembert (Peer reviewed; Journal article, 2019)
      Motivated by the important role of the normalized second-order coherence function, often called g(2), in the field of quantum optics, we propose a method to determine magnon coherence in solid-state devices. Namely, we ...
    • Spin Pumping from Uniform, Non-collinear Antiferromagnets 

      Lund, Mike Alexander (Master thesis, 2019)
      Motivert av nylig teoretisk arbeid med spin pumping i to-subgitter magneter vil vi undersøke effekten av kryss-subgitter spin pumping på den totale dc spin pumpestrømmen pumpet fra en antiferromagnet, og om dette kan bli ...