6 research outputs found
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