Spin-orbit torques from interfacial spin-orbit coupling for various interfaces

We use a perturbative approach to study the effects of interfacial spin-orbit coupling in magnetic multilayers by treating the two-dimensional Rashba model in a fully three-dimensional description of electron transport near an interface. This formalism provides a compact analytic expression for current-induced spin-orbit torques in terms of unperturbed scattering coefficients, allowing computation of spin-orbit torques for various contexts, by simply substituting scattering coefficients into the formulas. It applies to calculations of spin-orbit torques for magnetic bilayers with bulk magnetism, those with interface magnetism, a normal metal/ferromagnetic insulator junction, and a topological insulator/ferromagnet junction. It predicts a dampinglike component of spin-orbit torque that is distinct from any intrinsic contribution or those that arise from particular spin relaxation mechanisms. We discuss the effects of proximity-induced magnetism and insertion of an additional layer and provide formulas for in-plane current, which is induced by a perpendicular bias, anisotropic magnetoresistance, and spin memory loss in the same formalism.Comment: 24 pages, 9 figure

Progress toward the Enantioselective Synthesis of Curcusones A–D via a Divinylcyclopropane Rearrangement Strategy

We report our iterative efforts toward the divergent total syntheses of curcusones A–D via Suzuki coupling, intramolecular cyclopropanation, and a key divinylcyclopropane rearrangement. Progress of our synthesis was repeatedly challenged by the highly substrate-dependent cyclopropanation step, which we could ultimately overcome by judicious choice of substituents on the six-membered ring fragment

Measurement of the Translational Energy of Ions with a Time‐of‐Flight Mass Spectrometer

This is the publisher's version, also available electronically from http://scitation.aip.org/content/aip/journal/jcp/47/9/10.1063/1.1712366.A mathematical analysis of peak shapes in a Bendix time‐of‐flight mass spectrometer shows that ions formed with excess translational energy exhibit considerable peak broadening. A method is developed by which this translational energy can be readily determined from the peak width. Experimental results are presented which confirm the validity of the theoretical calculations

Optical Conductivity in Mott-Hubbard Systems

We study the transfer of spectral weight in the optical spectra of a strongly correlated electron system as a function of temperature and interaction strength. Within a dynamical mean field theory of the Hubbard model that becomes exact in the limit of large lattice coordination, we predict an anomalous enhancement of spectral weight as a function of temperature in the correlated metallic state and report on experimental measurements which agree with this prediction in $V_2O_3$. We argue that the optical conductivity anomalies in the metal are connected to the proximity to a crossover region in the phase diagram of the model.Comment: 12 pages and 4 figures, to appear in Phys. Rev. Lett., v 75, p 105 (1995