84,263 research outputs found
Nonequilibrium electron transport in strongly correlated molecular junctions
We investigate models of molecular junctions which constitute minimal
Hamiltonians to account for zero-bias-anomaly and the satellite features of
inelastic transport by molecular phonons. Through nonlinear transport
calculations with the imaginary-time nonequilibrium formalism, a HOMO-LUMO
model with Anderson-Holstein interaction is shown to produce co-tunneling
conductance peak in the vicinity of Kondo resonance which is mediated by a
re-emergent many-body resonance assisted by phonon excitations at bias equal to
the phonon frequency. Destruction of the resonance leads to
negative-differential-resistance in the sequential tunneling regime
Shock wave structure in a lattice gas
The motion and structure of shock and expansion waves in a simple particle system, a lattice gas and cellular automaton, are determined in an exact computation. Shock wave solutions, also exact, of a continuum description, a model Boltzmann equation, are compared with the lattice results. The comparison demonstrates that, as proved by Caprino et al. [“A derivation of the Broadwell equation,” Commun. Math. Phys. 135, 443 (1991)] only when the lattice processes are stochastic is the model Boltzmann description accurate. In the strongest shock wave, the velocity distribution function is the bimodal function proposed by Mott-Smith
Spin-triplet s-wave local pairing induced by Hund's rule coupling
We show within the dynamical mean field theory that local multiplet
interactions such as Hund's rule coupling produce local pairing
superconductivity in the strongly correlated regime. Spin-triplet
superconductivity driven by the Hund's rule coupling emerges from the pairing
mediated by local fluctuations in pair exchange. In contrast to the
conventional spin-triplet theories, the local orbital degrees of freedom has
the anti-symmetric part of the exchange symmetry, leaving the spatial part as
fully gapped and symmetric s-wave.Comment: 9 pages, 7 figure
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