Blar i NTNU Open på forfatter "Mæland, Kristian"
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Electron-magnon coupling and quasiparticle lifetimes on the surface of a topological insulator
Mæland, Kristian; Røst, Håkon Ivarssønn; Wells, Justin William; Sudbø, Asle (Peer reviewed; Journal article, 2021)The fermionic self-energy on the surface of a topological insulator proximity coupled to ferro- and antiferromagnetic insulators is studied. An enhanced electron-magnon coupling is achieved by allowing the electrons on the ... -
Exceeding the Chandrasekhar-Clogston limit in flat-band superconductors: A multiband strong-coupling approach
Mæland, Kristian; Sudbø, Asle (Peer reviewed; Journal article, 2023)Hybrid systems of superconductors and magnets display several intriguing properties, both from a fundamental physics point of view and with practical applications. Promising applications in superconducting spintronics ... -
Excitation Spectrum and Superfluidity of Weakly Interacting, Spin-Orbit Coupled Bose-Einstein Condensate
Mæland, Kristian (Master thesis, 2020)En svakt vekselvirkende, spinn-bane koblet, to-komponent, ultrakald Bose-gass bundet til et Bravais gitter blir studert. En analytisk framgangsmåte for å beskrive slike systemer i superfluid regimet blir presentert, motivert ... -
Magnon-Mediated Superconductivity: Investigating the Emergence of Strong Topological Superconductivity Mediated by Magnons in a Coplanar, Non-Collinear Magnet
Abnar, Sara (Master thesis, 2023)Denne masteroppgaven undersøker hvorvidt topologisk superledning kan oppstå i et todimensjonalt system bestående av et normalmetall og en magnet med koplanær spinnfase. Vi bygger videre på arbeidet til Mæland og Sudbø [1], ... -
Many-body effects and topology in magnets and superconductors
Mæland, Kristian (Doctoral theses at NTNU;2024:305, Doctoral thesis, 2024)Solid materials where quantum mechanical effects dominate the behavior can contribute to faster and more energy-efficient computers. The road to technological application starts with fundamental research. This thesis ... -
Many-body effects on superconductivity mediated by double-magnon processes in altermagnets
Mæland, Kristian; Brekke, Bjørnulf; Sudbø, Asle (Journal article; Peer reviewed, 2024)Altermagnets exhibit a large electron spin splitting which can be understood as a result of strong coupling between itinerant electrons and localized spins. We consider superconductivity due to electron-magnon scattering, ... -
Multiband strong-coupling superconductors with spontaneously broken time-reversal symmetry
Aase, Niels Henrik; Mæland, Kristian; Sudbø, Asle (Peer reviewed; Journal article, 2023)We study superconducting three-band systems within strong-coupling Eliashberg theory. In particular, we search for phase-frustrated superconducting systems with spontaneous time-reversal symmetry breaking (TRSB) states. ... -
Plane- and stripe-wave phases of a spin-orbit-coupled Bose-Einstein condensate in an optical lattice with a Zeeman field
Mæland, Kristian; Rygh, Jonas; Janssønn, Andreas; Sudbø, Asle (Peer reviewed; Journal article, 2020)A weakly interacting, spin-orbit-coupled, ultracold, dilute Bose gas on a two-dimensional square lattice with an external Zeeman field is studied. We explore the plane- and stripe-wave phases of the system involving nonzero ... -
Quantum fluctuations in the order parameter of quantum skyrmion crystals
Mæland, Kristian; Sudbø, Asle (Peer reviewed; Journal article, 2022)Traditionally, skyrmions are treated as continuum magnetic textures of classical spins with a well-defined topological skyrmion number. Owing to their topological protection, skyrmions have attracted great interest as ... -
Quantum topological phase transitions in skyrmion crystals
Mæland, Kristian; Sudbø, Asle (Peer reviewed; Journal article, 2022)Topological order is important in many aspects of condensed matter physics and has been extended to bosonic systems. In this Letter we report on the nontrivial topology of the magnon bands in two distinct quantum skyrmion ... -
Stability of superconducting gap symmetries arising from antiferromagnetic magnons
Sun, Chi; Mæland, Kristian; Sudbø, Asle (Peer reviewed; Journal article, 2023)We consider a planar heterostructure consisting of a normal metal in proximity to an antiferromagnetic insulator, with an interlayer exchange coupling between the metal and the insulator. The coupling to the two sublattices ... -
Strong-coupling approach to temperature dependence of competing orders of superconductivity: Possible time-reversal symmetry breaking and nontrivial topology
Sun, Chi; Mæland, Kristian; Thingstad, Even; Sudbø, Asle (Peer reviewed; Journal article, 2024)We use strong-coupling Eliashberg theory to study the competition of separate superconducting orders at low temperatures. Specifically, we study magnon-mediated superconductivity in a trilayer heterostructure with a thin ... -
Topological superconductivity mediated by magnons of helical magnetic states
Mæland, Kristian; Abnar, Sara; Benestad, Jacob Daniel; Sudbø, Asle (Peer reviewed; Journal article, 2023)We recently showed that spin fluctuations of noncoplanar magnetic states can induce topological superconductivity in an adjacent normal metal [Mæland et al., Phys. Rev. Lett. 130, 156002 (2023)]. The noncolinear nature of ... -
Topological Superconductivity Mediated by Skyrmionic Magnons
Mæland, Kristian; Sudbø, Asle (Peer reviewed; Journal article, 2023)Topological superconductors are associated with the appearance of Majorana bound states, with promising applications in topologically protected quantum computing. In this Letter, we study a system where a skyrmion crystal ...