dc.contributor.advisor Brataas, Arne nb_NO dc.contributor.author Gislesen, Halvor nb_NO dc.contributor.author Skarsvåg, Hans nb_NO dc.date.accessioned 2014-12-19T13:17:52Z dc.date.available 2014-12-19T13:17:52Z dc.date.created 2012-11-08 nb_NO dc.date.issued 2012 nb_NO dc.identifier 566409 nb_NO dc.identifier ntnudaim:8181 nb_NO dc.identifier.uri http://hdl.handle.net/11250/246783 dc.description.abstract We study the effect of an impurity potential on spin-memory loss in graphene. Various general methods for finding the spin-orbit related effect of a slowly varying impurity potential on a semiconductor have been examined. We have also revisited problems concerning electronic properties and spin relaxation in graphene. To this end, the bandstructure for graphene has been calculated through analytical and computational methods. The following results have been reproduced: Low energy excitations behave like massless relativistic particles with an effective speed of light at roughly 10^6 m/s. Intrinsic spin-orbit coupling splits the bands at the Fermi level. The importance of the $d$ orbitals for this effect is also shown. Extrinsic spin-orbit coupling induced by a perpendicular electric field give rise to a Rashba type Hamiltonian. Our novel results are related to extrinsic effects from an impurity. We have calculated the renormalised impurity induced spin-orbit coupling due to mixing of the conduction bands and the other bands. This renormalisation is at most comparable to the vacuum term, and thus cannot explain the experimental results on spin relaxation. nb_NO dc.language eng nb_NO dc.publisher Institutt for fysikk nb_NO dc.subject ntnudaim:8181 no_NO dc.subject MTFYMA fysikk og matematikk no_NO dc.subject Teknisk fysikk no_NO dc.title Renormalised Intrinsic and Extrinsic Impurity Induced Spin-orbit Scattering in Graphene nb_NO dc.type Master thesis nb_NO dc.source.pagenumber 113 nb_NO dc.contributor.department Norges teknisk-naturvitenskapelige universitet, Fakultet for naturvitenskap og teknologi, Institutt for fysikk nb_NO
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