659 research outputs found
Correlation energy in a spin polarized two dimensional electron liquid in the high density limit
We have obtained an analytic expression for the ring diagrams contribution to
the correlation energy of a two dimensional electron liquid as a function of
the uniform fractional spin polarization. Our results can be used to improve on
the interpolation formulas which represent the basic ingredient for the
constructions of modern spin-density functionals in two dimensions.Comment: 3 pages, 1 figur
Two exact properties of the perturbative expansion for the two-dimensional electron liquid with Rashba or Dresselhaus spin-orbit coupling
We have identified two useful exact properties of the perturbative expansion
for the case of a two-dimensional electron liquid with Rashba or Dresselhaus
spin-orbit interaction and in the absence of magnetic field. The results allow
us to draw interesting conclusions regarding the dependence of the exchange and
correlation energy and of the quasiparticle properties on the strength of the
spin-orbit coupling which are valid to all orders in the electron-electron
interaction.Comment: 6 pages, 1 figur
High density limit of the two-dimensional electron liquid with Rashba spin-orbit coupling
We discuss by analytic means the theory of the high-density limit of the
unpolarized two-dimensional electron liquid in the presence of Rashba or
Dresselhaus spin-orbit coupling. A generalization of the ring-diagram expansion
is performed. We find that in this regime the spin-orbit coupling leads to
small changes of the exchange and correlation energy contributions, while
modifying also, via repopulation of the momentum states, the noninteracting
energy. As a result, the leading corrections to the chirality and total energy
of the system stem from the Hartree-Fock contributions. The final results are
found to be vanishing to lowest order in the spin-orbit coupling, in agreement
with a general property valid to every order in the electron-electron
interaction. We also show that recent quantum Monte Carlo data in the presence
of Rashba spin-orbit coupling are well understood by neglecting corrections to
the exchange-correlation energy, even at low density values.Comment: 11 pages, 5 figure
Exchange energy and generalized polarization in the presence of spin-orbit coupling in two dimensions
We discuss a general form of the exchange energy for a homogeneous system of
interacting electrons in two spatial dimensions which is particularly suited in
the presence of a generic spin-orbit interaction. The theory is best formulated
in terms of a generalized fractional electronic polarization. Remarkably we
find that a net generalized polarization does not necessarily translate into an
increase in the magnitude of the exchange energy, a fact that in turn favors
unpolarized states. Our results account qualitatively for the findings of
recent experimental investigations
Shell morphology of the Egyptian tortoise, Testudo kleinmanni Lortet, 1883, the osteologically least-known Testudo species.
Plasmon mass and Drude weight in strongly spin-orbit-coupled 2D electron gases
Spin-orbit-coupled two-dimensional electron gases (2DEGs) are a textbook
example of helical Fermi liquids, i.e. quantum liquids in which spin (or
pseudospin) and momentum degrees-of-freedom at the Fermi surface have a
well-defined correlation. Here we study the long-wavelength plasmon dispersion
and the Drude weight of archetypical spin-orbit-coupled 2DEGs. We first show
that these measurable quantities are sensitive to electron-electron
interactions due to broken Galileian invariance and then discuss in detail why
the popular random phase approximation is not capable of describing the
collective dynamics of these systems even at very long wavelengths. This work
is focussed on presenting approximate microscopic calculations of these
quantities based on the minimal theoretical scheme that captures the basic
physics correctly, i.e. the time-dependent Hartree-Fock approximation. We find
that interactions enhance the "plasmon mass" and suppress the Drude weight. Our
findings can be tested by inelastic light scattering, electron energy loss, and
far-infrared optical-absorption measurements.Comment: 18 pages, 11 figures, submitte
Anomalous spin-resolved point-contact transmission of holes due to cubic Rashba spin-orbit coupling
Evidence is presented for the finite wave vector crossing of the two lowest
one-dimensional spin-split subbands in quantum point contacts fabricated from
two-dimensional hole gases with strong spin-orbit interaction. This phenomenon
offers an elegant explanation for the anomalous sign of the spin polarization
filtered by a point contact, as observed in magnetic focusing experiments.
Anticrossing is introduced by a magnetic field parallel to the channel or an
asymmetric potential transverse to it. Controlling the magnitude of the
spin-splitting affords a novel mechanism for inverting the sign of the spin
polarization.Comment: 4 pages, 3 figure
A preliminary description of new Late Cretaceous chelonian remains from Sant’Anna di Alfaedo (Verona, Italy)
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