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1	Quantum structure of holographic black holes / Kvantstruktur hos holografiska svarta hål Riedel Gårding, Elias January 2020 (has links) We study a free quantum scalar field in the BTZ spacetime as a model of the AdS/CFT correspondence for black holes, and show the essential steps in computing Bogolyubov coefficients between modes on either side of the wormhole. As background, we review the BTZ geometry in standard, Kruskal and Poincaré coordinates, holographic renormalisation of the dual field theory and canonical quantisation in curved spacetime. / Vi studerar ett fritt skalärt kvantfält i BTZ-rumtiden som en modell av AdS/CFT-dualiteten för svarta hål och visar huvudstegen i beräkningen av Bogolyubov-koefficienter mellan moder på olika sidor av maskhålet. Som bakgrund redogör vi för BTZ-geometrin i standard-, Kruskal- och Poincarékoordinater, holografisk renormering av den duala fältteorin och kanonisk kvantisering i krökt rumtid. BTZ spacetime black hole wormhole AdS/CFT holographic renormalisation analytic continuation Bogolyubov transformation QFT in curved spacetime BTZ-rumtid svart hål maskhål AdS/CFT holografisk renormering analytisk fortsättning Bogolyubov-transformation kvanfältsteori i krökt rumtid Physical Sciences Fysik
2	Non-Orthogonality and Electron Correlations in Nanotransport : Spin- and Time-Dependent Currents Fransson, Jonas January 2002 (has links) <p>The concept of the transfer Hamiltonian formalism has been reconsidered and generalized to include the non-orthogonality between the electron states in an interacting region, e.g. quantum dot (QD), and the states in the conduction bands in the attached contacts. The electron correlations in the QD are described by means of a diagram technique for Hubbard operator Green functions for non-equilibrium states. </p><p>It is shown that the non-orthogonality between the electrons states in the contacts and the QD is reflected in the anti-commutation relations for the field operators of the subsystems. The derived forumla for the current contains corrections from the overlap of the same order as the widely used conventional tunneling coefficients. </p><p>It is also shown that kinematic interactions between the QD states and the electrons in the contacts, renormalizes the QD energies in a spin-dependent fashion. The structure of the renormalization provides an opportunity to include a spin splitting of the QD levels by polarizing the conduction bands in the contacts and/or imposing different hybridizations between the states in the contacts and the QD for the two spin channels. This leads to a substantial amplification of the spin polarization in the current, suggesting applications in magnetic sensors and spin-filters.</p> Physics non-orthogonality non-equilibrium transport nanosystem quantum dot spin-dependent renormalization Green function diagram technique many-body states Hubbard operator electron correlations time-dependent Fysik icke-ortogonal icke-jämvikt transport nanosystem kvantprick spinberoende renormering Green-funktion diagramteknik mångkropparstillstånd Hubbadoperator elektronkorrelationer tidsberoende Physics Fysik
3	Non-Orthogonality and Electron Correlations in Nanotransport : Spin- and Time-Dependent Currents Fransson, Jonas January 2002 (has links) The concept of the transfer Hamiltonian formalism has been reconsidered and generalized to include the non-orthogonality between the electron states in an interacting region, e.g. quantum dot (QD), and the states in the conduction bands in the attached contacts. The electron correlations in the QD are described by means of a diagram technique for Hubbard operator Green functions for non-equilibrium states. It is shown that the non-orthogonality between the electrons states in the contacts and the QD is reflected in the anti-commutation relations for the field operators of the subsystems. The derived forumla for the current contains corrections from the overlap of the same order as the widely used conventional tunneling coefficients. It is also shown that kinematic interactions between the QD states and the electrons in the contacts, renormalizes the QD energies in a spin-dependent fashion. The structure of the renormalization provides an opportunity to include a spin splitting of the QD levels by polarizing the conduction bands in the contacts and/or imposing different hybridizations between the states in the contacts and the QD for the two spin channels. This leads to a substantial amplification of the spin polarization in the current, suggesting applications in magnetic sensors and spin-filters. Physics non-orthogonality non-equilibrium transport nanosystem quantum dot spin-dependent renormalization Green function diagram technique many-body states Hubbard operator electron correlations time-dependent Fysik icke-ortogonal icke-jämvikt transport nanosystem kvantprick spinberoende renormering Green-funktion diagramteknik mångkropparstillstånd Hubbadoperator elektronkorrelationer tidsberoende Physics Fysik

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