Spin polarization in the Hubbard model with Rashba spin-orbit coupling on a ladder

Abstract

The competition between on-site Coulomb repulsion and Rashba spin-orbit coupling (RSOC) is studied on two-leg ladders by numerical techniques. By studying persistent currents in closed rings by exact diagonalization, it is found that the contribution to the current due to the RSOC V_{SO}, for a fixed value of the Hubbard repulsion U reaches a maximum at intermediate values of V_{SO}. By increasing the repulsive Hubbard coupling U, this spin-flipping current is suppressed and eventually it becomes opposite to the spin-conserving current. The main result is that the spin accumulation defined as the relative spin polarization between the two legs of the ladder is enhanced by U. Similar results for this Hubbard-Rashba model are observed for a completely different setup in which two halves of the ladders are connected to a voltage bias and the ensuing time-dependent regime is studied by the density matrix-renormalization group technique. It is also interesting a combined effect between V_{SO} and U leading to a strong enhancement of antiferromagnetic order which in turn may explain the observed behavior of the spin-flipping current. The implications of this enhancement of the spin-Hall effect with electron correlations for spintronic devices is discussed.

7 pages, 8 figures

References in corpus (10)

• Dissipationless Quantum Spin Current at Room Temperature
• Novel Jeff = 1/2 Mott State Induced by Relativistic Spin-Orbit Coupling in Sr2IrO4
• Spin-orbit coupling in curved graphene, fullerenes, nanotubes, and nanotube caps
• Can Non-Equilibrium Spin Hall Accumulation be Induced in Ballistic Nanostructures?
• Persistent current in ballistic mesoscopic rings with Rashba spin-orbit coupling
• Time-step targetting methods for real-time dynamics using DMRG
• Spin states and persistent currents in mesoscopic rings: spin-orbit interactions
• Flat bands with higher Chern number in pyrochlore slabs
• Few-electron physics in a nanotube quantum dot with spin-orbit coupling
• The two-impurity Kondo model with spin-orbit interactions

Cited by in corpus (12)

• The evolution of magnetic structure driven by a synthetic spin-orbit coupling in two-component Bose-Hubbard model
• Quantum phases of 1D Hubbard models with three- and four-body couplings
• Theory of Supercurrent in Superconductors
• Magnetic and transport signatures of Rashba spin-orbit coupling on the ferromagnetic Kondo lattice model in two dimensions
• Equivalence of Rashba-Hubbard and Hubbard chains
• Spin-orbit coupled fermions in ladder-like optical lattices at half-filling
• Helical currents in metallic Rashba strips
• Phase diagram, band structure and density of states in two-dimensional attractive Fermi-Hubbard model with Rashba spin-orbit coupling
• Longitudinal optical and spin-Hall conductivities of Rashba conducting strips coupled to ferro- and antiferromagnetic layers
• Berry connection from many-body wave functions and superconductivity: Calculations by the particle number conserving Bogoliubov-de Gennes equations
• Construction of the spectral function from non-commuting spectral moment matrices
• Transport properties of Rashba conducting strips coupled to magnetic moments with spiral order