The hyperfine interaction between carrier spins and nuclear spins is an important component in exploring spin-dependent properties in materials with strong spin orbit interaction.However hyperfine interaction has been less studied in bismuth (Bi), a heavy element exhibiting a strong Rashba-like spin-orbit interaction in its two-dimensional surface states due to the broken spatial inversion symmetry. A differential conductance measurement of the InSb/CoFe interface during spin injection indicates a quasiparticle gap present at the Fermi energy, coinciding with the large magnetoresistance. The low-"field high resistance state has similar temperature and magnetic "field dependences as the superconducting phase, but a superconducting component in the device measurements seems absent. For temperatures below 3.5 K, a large, symmetric, and abrupt negative magnetoresistance is observed. InSb/CoFe junctions are studied as InSb "films are a simpler spin-orbit coupled system compared to Bi "films. The anisotropic magnetoresistance of the CoFe is modifi"ed when carriers tunnel into the CoFe from Bi, possibly due to a spin dependent tunneling process or an interaction between the spin polarized density of states in CoFe and the anisotropic spin-orbit coupled density of states in Bi. To probe the Bi surface state further, Bi/CoFe junctions are fabricated. This is a consequence of the quantum transport contribution from the strongly spin-orbit coupled Bi(001) surface state. The spin coherence length is independent of dimensional constraint by the film thickness, but increases significantly as the lateral dimensions, such as wire width, are constrained. Dephasing due to quantum confinement e"ffects limit the phase coherence in small Bi structures, impairing the observation of controlled interference phenomena in nano-scale Bi rings. Specifically, in Bi wires, the phase coherence length is approximately as long as the wire width. The "findings indicate that the phase coherence scales proportionally to the limiting dimension of the structure for sizes less than 500 nm. The phase and spin coherence of Bi geometries constrained in one, two, and three dimensions are systematically studied by analysis of the weak antilocalization transport signature, a quantum interference phenomenon sensitive to spin-orbit coupling. Morphologically and electrically high quality "films are grown using a two stage deposition procedure. The characteristics of Bi "film growth by thermal evaporation is provided. The experiments performed study the quantum transport signatures of nano- and micron-scale lithographically defined devices as well as spin-orbit coupled material/ferromagnet interfaces.Īll Bi structures are fabricated from Bi thin "films, and hence a detailed analysis of This dissertation focuses on the characteristics of elemental bismuth (Bi), which exhibits some of the strongest intrinsic spin-orbit coupling of all elements, and InSb, which exhibits some of the strongest intrinsic spin-orbit coupling of all compound semiconductors. VSe electron−electron interactions spin−orbit coupling sublimed-salt-assisted chemical vapor deposition weak antilocalization effect.Systems with strong spin-orbit coupling are of particular interest in solid state physics as an avenue for observing and manipulating spin physics using standard electrical techniques. Such sublimed-salt-assisted growth of high-quality few-layered VSe 2 and the observation of WAL pave the way for future spintronic and valleytronic applications. The phase coherence length l ϕ shows a power law dependence with temperature, l ϕ∼ T -1/2, revealing an electron-electron interaction-dominated dephasing mechanism. The WAL magnitudes in magnetoconductance can be perfectly fitted by the 2D Hikami-Larkin-Nagaoka (HLN) equation in the presence of strong SOC, by which the spin-orbit scattering length l SO and phase coherence length l ϕ have been extracted. Here, we report on the observation of quasi-2D transport and WAL effect in sublimed-salt-assisted low-temperature chemical vapor deposition (CVD) grown few-layered high-quality VSe 2 nanosheets. The observation of WAL effect in VSe 2 is challenging due to the relative weak SOC and three-dimensional (3D) transport nature in thick VSe 2. With strong spin-orbit coupling (SOC), ultrathin two-dimensional (2D) transitional metal chalcogenides (TMDs) are predicted to exhibit weak antilocalization (WAL) effect at low temperatures.
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