Spin-orbit strip systems with strong electronic correlations

C. J. GAZZA; JOSÉ A. RIERA; I.J. HAMAD

Praga

Conferencia; International Conference on Strongly Correlated Electron Systems, SCES; 2017

We study metallic strips in the presence of spin-orbit coupling at zero temperature. We first focus on strips with Rashba spin-orbit coupling (RSOC) [1] . We study the Rashba helical currents (RHC) (i.e. spin-up and spin-down charge electron currents that flow in opposite directions) and the spin accumulation for the noninteracting case in rings and in open strips, with and without external electromagnetic sources. We determine the distribution across the strip section of the RHC, as a function of the RSOC strength, strip width and electron filling. We then focus on strips with RSOC and on-site Hubbard repulsion U. Electron correlations are present in a number of surfaces and interfaces involving transition metal oxides. We show that these RHC remain in the presence of U at quarter filling, where the system remains metallic, and even at half-filling where a Mott-Hubbard metal-insulator transition occurs for largeHubbard repulsion [1]. We use a variety of numerical methods, including exact diagonalization, variational Monte Carlo, and the time-dependent Density Matrix Renormalization Group method for the interacting case. We then show results for the optical and spin-hall conductivities for noninteracting strips coupled to Ferromagnetic and Antiferromangetic layers [2]. Finally, we study strips with both Rashba and Dresselhauss spin orbit coupling, both in the noninteracting and in the interacting case for different fillings, and show that when the Rashba and Dresselhaus couplings are equal, the RHC vanish [3].