Blar i NTNU Open på forfatter "Kamra, Akashdeep"
-
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 ... -
Interfacial control of vortex-limited critical current in type-II superconductor films
Hope, Marius Kalleberg (Master thesis, 2021)Ginzburg-Landau (GL)-teorien for superledning i kombinasjon med spinn-bane-kobling er brukt til å beregne kritisk strøm i type-II superledende tynne filmer med Rashba spinn-bane-kobling. Formalismen som er benyttet her er ... -
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 ... -
Phase-controlled spin and charge currents in a superconductor-ferromagnet hybrid
Rezaei, Ali; Hussein, Robert; Kamra, Akashdeep; Belzig, Wolfgang (Peer reviewed; Journal article, 2020)We investigate spin-dependent quasiparticle and Cooper-pair transport through a central node interfaced with two superconductors and two ferromagnets. We demonstrate that voltage biasing of the ferromagnetic contacts induces ... -
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 ... -
Tunable anisotropic quantum Rabi model via magnon|spin-qubit ensemble
Skogvoll, Ida Cathrine (Master thesis, 2021)Den pågående utviklingen innenfor kvanteinformasjonteknologi står ovenfor en rekke utfordringer i forbindelse med å konstruere fysiske plattformer som vil kunne være med på å realisere kvanteberegning og kvantekommunikasjon. ...