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Non-Centrosymmetric Superconductivity And Magnetism In The Presence Of Broken Symmetries, Mojammel Alam Khan

LSU Doctoral Dissertations

Non-centrosymmetric (NC) superconducting and magnetic compounds have been synthesized and investigated using magnetic, specific heat, and transport measurements, as well as by neutron scattering and quantum oscillations. The crystal structures of NC compounds are defined by the lack of an inversion center. In NC superconductors, a finite antisymmetric spin orbit coupling originating from broken inversion symmetry results in unconventional Cooper pairing. Instead of a single spin channel, the order parameter is a mixture of spin-singlet and spin-triplet states. For NC magnetic compounds, the antisymmetric and isotropic spin interactions compete, leading to a helical ground state.

We have studied the NC …

Exact Numerical Study Of Disordered Systems, Conrad Wilson Moore

LSU Doctoral Dissertations

This thesis presents work on the development of new techniques to study the problem of localization in various models of disordered systems with the goal of being able to extend these model calculations to real materials where these various mechanisms of disorder can all be present. I consider the Anderson Model with diagonal, off-diagonal disorder, multiple bands and superconductivity is included at the level of a Bogoliubov - De Gennes mean field (superconductivity is considered by adding the symmetries of the Bogoliubov - De Gennes Hamiltonian on top of the disordered lattice Hamiltonian). The localization of electrons is studied with …