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

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

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

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

On the RKKY range function of a one dimensional non interacting electron gas

We show that the pitfalls encountered in earlier calculations of the RKKY range function for a non interacting one dimensional electron gas at zero temperature can be unraveled and successfully dealt with through a proper handling of the impurity potential.Comment: to appear in Phys. Re

Spin Instabilities in Semiconductor Superlattices

The subband levels of quantum wells grown in a periodic array form minibands whose bandwidth ⌬ depends on the probability of interlayer tunneling. In the presence of a strong magnetic field, this system of minibands can exhibit various Coulomb-interaction-driven spin polarization instabilities at an integral value of the filling factor ␯. We investigate in particular the Hartree-Fock phase diagram in the case in which the nϭ0 spin-up and nϭ1 spin-down Landau levels are separated by an energy smaller than ⌬. A spin-density-wave ground state is shown to occur at filling factor ␯ϭ2

Tunneling Between Dissimilar Quantum Wells: A Probe of the Energy-Dependent Quasiparticle Lifetime

Tunneling between two narrow quantum wells with different effective masses is proposed as a probe of the quasiparticle inelastic lifetime at finite excitation energy. Conservation of energy and of kជ, the momentum parallel to the interface, allows the tunneling conductance to be large only if the crossing of the two energy bands ͓E1(kជ)ϭE2(kជ)ϩeV͔ at an applied voltage V occurs between the two Fermi levels. The abruptness of the change in tunneling current as this crossing passes through one of the Fermi levels can be used to investigate the lifetimes of the quasiparticle states involved. Results based on the random phase approximation are used as an illustration

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

Critical current of a long Josephson junction in the presence of a perturbing Abrikosov vortex

We investigate theoretically how the proximity of an Abrikosov vortex influences the physical properties of a long Josephson junction. We find that ␦I c , the contribution to the critical current associated with the presence of the vortex, is generally positive ͑the critical current is increased͒ and is crucially dependent on the specific boundary conditions satisfied by the transport current. In the case in which the latter has a bulk component in the vicinity of the vortex, ␦I c is proportional to the coupling between the vortex and the junction. The situation is however more complex when the transport current is purely a surface phenomenon. In this case ␦I c strongly depends on the distance between the vortex and the edges of the junction, and is in general much smaller than that of the bulk current case unless a special commensurability condition is met. In particular we show that a contribution to ␦I c proportional to is obtained in this case only when an integer number of Josephson vortices can be accommodated between the location of the vortex and one of the edges of the junction