Spin susceptibilities, spin densities and their connection to spin-currents

We calculate the frequency dependent spin susceptibilities for a two-dimensional electron gas with both Rashba and Dresselhaus spin-orbit interaction. The resonances of the susceptibilities depends on the relative values of the Rashba and Dresselhaus spin-orbit constants, which could be manipulated by gate voltages. We derive exact continuity equations, with source terms, for the spin density and use those to connect the spin current to the spin density. In the free electron model the susceptibilities play a central role in the spin dynamics since both the spin density and the spin current are proportional to them.Comment: 6 pages, revtex4 styl

Finite temperature spectral-functions of strongly correlated one-dimensional electron systems

The spectral functions of tJ and tJ_{XY} models in the limit of J/t-> 0 and at finite temperatures T>>t are calculated using the spin-charge factorized wave function. We find that the Luttinger-liquid like scaling behavior for a finite system with L sites is restricted below temperatures of the order T = J/L. We also observe weight redistribution in the photoemission spectral function in the energy range t, which is much larger than the temperature.Comment: revtex, 4 pages, 3 eps figure

Spectral functions of the 1D Hubbard model in the U -> \infty limit: How to use the factorized wave-function

We give the details of the calculation of the spectral functions of the 1D Hubbard model using the spin-charge factorized wave-function for several versions of the U -> +\infty limit. The spectral functions are expressed as a convolution of charge and spin dynamical correlation functions. A procedure to evaluate these correlation functions very accurately for large systems is developed, and analytical results are presented for the low energy region. These results are fully consistent with the conformal field theory. We also propose a direct method of extracting the exponents from the matrix elements in more general cases.Comment: 15 pages,7 eps figures, RevTeX, needs epsf and multico

Charge-Spin Separation and the Spectral Properties of Luttinger Liquids

We compute the spectral function rho(q,omega) of the one- dimensional Luttinger model. We discuss the distinct influences of charge-spin separation and of the anomalous dimensions of the fermion operators and their evolution with correlation strength. Charge-spin separation shows up in finite spectral weight at frequencies between v_sigma * q and v_rho * q where v_rho and v_sigma are the velocities of charge and spin fluctuations while spectral weight above v_rho * q and below -v_rho * q is generated by the hybridization of the Fermi surface at +/-k_F by interactions. There are nonuniversal power-law singularities at these special frequencies. We discuss the consistency of recent photoemission experiments on low-dimensional conductors with a Luttinger liquid picture which then would suggest very strong long- range interactions. It is pointed out that many-particle correlation functions in principle exhibit similar singularities but they probe different and complementary aspects of the Fermi surface interactions.Comment: 8 pages (identical) + 3 figures (file replaced), Latex, ILL-SP-93-VO506