Browsing NTNU Open by Author "Sudbø, Asle"
Now showing items 21-40 of 47
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Maximum Entropy and Maximum Entropy Production in Macroecology
Sognnæs, Ida Andrea Braathen (Master thesis, 2011)The Maximum Entropy Theory of Ecology (METE), developed by John Harte, presents an entirely new method of making inferences in ecology. The method is based on the established mathematical procedure of Maximum Information ... -
Phase structure and critical properties of an abelian gauge theory
Mo, Sjur (Dr. ingeniøravhandling, 0809-103X; 2001:116, Doctoral thesis, 2002)Chapter 1 to 4 give a short introduction to superconductivity, microscopic theory, phase transitions, and Monte-Carlo simulations. Chapter 2 is about Cooper pairing in different settings, but I also give a short introduction ... -
Phase-controlled proximity effect in ferromagnetic Josephson junctions: Calculation of the density of states and the electronic specific heat
Alidoust, Mohammad; Rashedi, Gholamreza; Linder, Jacob; Sudbø, Asle (Journal article; Peer reviewed, 2010)We study the thermodynamic properties of a dirty ferromagnetic S|F|S Josephson junction with s-wave superconducting leads in the low-temperature regime. We employ a full numerical solution with a set of realistic parameters ... -
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 ... -
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 ... -
Possible odd-frequency Amperean magnon-mediated superconductivity in topological insulator–ferromagnetic insulator bilayer
Hugdal, Henning Goa; Sudbø, Asle (Journal article; Peer reviewed, 2020)We study the magnon-mediated pairing between fermions on the surface of a topological insulator (TI) coupled to a ferromagnetic insulator with a tilted mean field magnetization. Tilting the magnetization toward the interfacial ... -
Pressure-induced 0-π transitions and supercurrent crossover in antiferromagnetic weak links
Enoksen, Henrik; Linder, Jacob; Sudbø, Asle (Journal article, 2013)We compute self-consistently the Josephson current in a superconductor-antiferromagnet-superconductor junction using a lattice model, focusing on 0−π transitions occurring when the width of the antiferromagnetic region ... -
Probing phase separation in Bose-Fermi mixtures by the critical superfluid velocity
Linder, Jacob; Sudbø, Asle (Journal article; Peer reviewed, 2010)We investigate the effect exerted by spin-polarized fermions on the interaction between superfluid bosons for a Bose-Fermi mixture residing on an optical lattice, with particular emphasis on the possibility of an induced ... -
Proximity effects in superconducting hybrid structures with spin-dependent interactions
Amundsen, Morten (Doctoral theses at NTNU;2020:243, Doctoral thesis, 2020)When superconductors are contacted by other, non-superconducting materials, the latter may attain some of the properties of the former, and vice versa. This is the origin of a wealth of interesting phenomena. A striking ... -
Pure spin current generated by reflection at a normal metal/two-dimensional electron gas interface
Linder, Jacob; Yokoyama, Takehito; Sudbø, Asle (Journal article; Peer reviewed, 2010)The concept of a spin current is a useful tool in understanding spin transport in hybrid systems but its very definition is problematic in systems where spin-orbit coupling effects are strong. In the absence of spin-dependent ... -
Quantum Monte Carlo Simulations of Drag Interaction in the Superfluid Phase of the 3-Component Bose-Hubbard Model
Erlandsen, Eirik (Master thesis, 2018)We study Andreev-Bashkin drag interactions between the superflow of different components in the superfluid phase of a three-component Bose-Hubbard model without component-mixing interactions, relevant for cold atom systems ... -
Schwinger boson study of superconductivity mediated by antiferromagnetic spin fluctuations
Erlandsen, Eirik; Sudbø, Asle (Peer reviewed; Journal article, 2020)We study superconductivity in a normal metal, arising from effective electron-electron interactions mediated by spin fluctuations in a neighboring antiferromagnetic insulator. Introducing a frustrating next-nearest neighbor ... -
Signature of odd-frequency pairing correlations induced by a magnetic interface
Linder, Jacob; Sudbø, Asle; Yokoyama, Takehito; Grein, Roland; Eschrig, Matthias (Journal article; Peer reviewed, 2010)We investigate the mutual proximity effect in a normal metal contacted to a superconductor through a magnetic interface. Analytical and self-consistent numerical results are presented, and we consider both the diffusive ... -
Spin-active interfaces and unconventional pairing in half-metal/superconductor junctions
Linder, Jacob; Cuoco, Mario; Sudbø, Asle (Journal article; Peer reviewed, 2010)We study the physical properties of a half-metallic ferromagnet∣superconductor (HM∣S) bilayer, allowing for an arbitrary bulk pairing symmetry of the superconductor and spin-dependent processes at the interface. In particular, ... -
Spin-flip scattering and critical currents in ballistic half-metallic d-wave Josephson junctions
Enoksen, Henrik; Linder, Jacob; Sudbø, Asle (Journal article, 2012)We analyze the dc Josephson effect in a ballistic superconductor/half-metal/superconductor junction by means of the Bogoliubov–de Gennes equations. We study the role of spin-active interfaces and compare how different ... -
Spin-orbit coupled multiband superconductors
Gunnarsen, Gudmund (Master thesis, 2016)A model for square lattice spin orbit coupled cooper pairing is derived using mean field theory. We look at three cases, a magnetic field parallel to the lattice, perpendicular to the lattice, and no magnetic field. For ... -
Spin-polarized Josephson current in superconductor/ferromagnet/superconductor junctions with inhomogeneous magnetization
Alidoust, Mohammad; Linder, Jacob; Rashedi, Gholamreza; Yokoyama, Takehito; Sudbø, Asle (Journal article; Peer reviewed, 2010)We study numerically the properties of spin transport and charge transport in a current-biased nanoscale diffusive superconductor/ferromagnet/superconductor junction when the magnetization texture is nonuniform. Specifically, ... -
Spin-sensitive long-range proximity effect in ferromagnet/spin-triplet-superconductor bilayers
Annunziata, Gaetano; Cuoco, Mario; Noce, Canio; Sudbø, Asle; Linder, Jacob (Journal article; Peer reviewed, 2011)The discovery of noncentrosymmetric superconductors, such as CePt3Si, and chiral superconductors, such as Sr2RuO4, calls for experimental methods to identify the presence of spin-triplet pairing. We here demonstrate a ... -
A study of proximity-induced and magnon-mediated superconductivity on the surface of topological insulators
Hugdal, Henning Goa (Doctoral theses at NTNU;2021:40, Doctoral thesis, 2020)Summary: This thesis presents a study of superconducting phases in different effectively two-dimensional (2D) systems with spin-orbit coupling, with particular emphasis on systems consisting topological insulators (TIs) ... -
Superconductivity in Dirac Materials
Sjømark, Severin Bøyesen (Master thesis, 2016)In this Master s thesis we consider superconductivity in Bravais and bipartite lattice fermion models with nearest neighbour hopping and Rashba-type spin-orbit coupling. The superconductivity is modelled from a negative-U ...