Dingping Li

Enhancement of polarization in a spin-orbit coupling quantum wire with a constriction

We investigate the enhancement of spin polarization in a quantum wire in the presence of a constriction and a spin-orbit coupling segment. It is shown that the spin-filtering effect is significantly heightened in comparison with the configuration without the constriction. It is understood in the studies that the constriction structure plays a critical role in enhancing the spin filtering by means of confining the incident electrons to occupy one channel only while the outgoing electrons occupy two channels. The enhancement of spin filtering has also been analyzed within the perturbation theory. Because the spin polarization arises mainly from the scattering between the constriction and the segment with spin-orbit coupling, the subband mixing induced by spin-orbit interaction in the scattering process and the inferences result in higher spin-filtering effect.

Electrical conductivity beyond a linear response in layered superconductors under a magnetic field

The time-dependent Ginzburg-Landau approach is used to investigate nonlinear response of a strongly type-II superconductor. The dissipation takes a form of the flux flow which is quantitatively studied beyond linear response. Thermal fluctuations, represented by the Langevin white noise, are assumed to be strong enough to melt the Abrikosov vortex lattice created by the magnetic field into a moving vortex liquid and marginalize the effects of the vortex pinning by inhomogeneities. The layered structure of the superconductor is accounted for by means of the Lawrence-Doniach model. The nonlinear interaction term in dynamics is treated within self-consistent Gaussian approximation and we go beyond the often used lowest Landau level approximation to treat arbitrary magnetic fields. The I-V curve is calculated for arbitrary temperature and the results are compared to experimental data on high-T(c.) superconductor YBa(2)Cu(3)O(7-delta).

Unconventional thermoelectric behaviors and enhancement of figure of merit in Rashba spintronic systems

Thermoelectric transport in strongly spin-orbit coupled two-dimensional Rashba system is studied using the exact solution of the linearized Boltzmann equation. Some unusual transport behaviors are revealed. We show that the electrical conductivity takes a Drude form when the Fermi energy

LOWEST LANDAU LEVEL APPROXIMATION IN STRONGLY TYPE-II SUPERCONDUCTORS

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Effect of the type-I to type-II Weyl semimetal topological transition on superconductivity

is above the band crossing point, but a non-Drude form which is a quadratic function of

Strong thermal fluctuations in cuprate superconductors in magnetic fields above T-c

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Strong magnetic field induces superconductivity in a Weyl semimetal

when

Superconductivity in the two-dimensional electron gas induced by high-energy optical phonon mode and large polarization of the SrTiO3 substrate

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Magnetic properties of Type I and II Weyl Superconductors.

lies below the band crossing point. The Mott relation breaks down when

Magnetic impurities make superconductivity in 3D Dirac semi-metal triplet

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