Hyperfine and electric quadrupolar interaction-driven loschmidt echo in nanoscale nuclear spin baths

dc.contributor.advisorBulutay, Ceyhun
dc.contributor.authorGüldeste, Ekrem Taha
dc.departmentDepartment of Physicsen_US
dc.descriptionCataloged from PDF version of article.en_US
dc.descriptionThesis (M.S.): Bilkent University, Department of Physics, İhsan Doğramacı Bilkent University, 2018.en_US
dc.descriptionIncludes bibliographical references (leaves 36-42).en_US
dc.description.abstractEnvironmental dynamics in solid state matrix is of much importance for quantum information processing and storage purposes. Here, we first give a basic recipe to get Loschmidt echo (LE) which is a measure of decoherence (loss of information from the qubit) in heterogeneously interacting nuclear spin bath (NSB) in the presence of Fermi-contact hyperfine and nuclear spin dipole-dipole interactions. Then, by dropping the latter we discuss the basic dependencies of pure-dephasing regime on size, initial polarization, hyperfine coupling inhomogeneity, spin quantum number in nuclear spin environments, and arrive at a phenomenological expression that governs all these attributes. For NSBs consisting of spin-I ≥ 1, the effect of nuclear electric quadrupole interaction is also considered where its biaxiality term has an in uence on the decoherence process. Furthermore, a general decoherence channel is also employed to see how phase- ip rate affects LE. After insights gained from these models, we consider two generic realistic systems, namely, donor center and quantum dot and explain the power spectral density of LE in these cases.en_US
dc.description.statementofresponsibilityby Ekrem Taha Güldeste.en_US
dc.format.extentx, 50 leaves : graphics, 30 cmen_US
dc.publisherBilkent Universityen_US
dc.subjectQubit Decoherenceen_US
dc.subjectCentral Spin Decoherenceen_US
dc.subjectLoschmidt Echoen_US
dc.subjectNuclear Spin Bathsen_US
dc.titleHyperfine and electric quadrupolar interaction-driven loschmidt echo in nanoscale nuclear spin bathsen_US
dc.title.alternativeNano ölçekli spin hamamları için enaltyapı ve dörtkutup etkileşimleri altında loschmidt yankısıen_US