Aleiner, Igor L. | Engineering Papers

DOE OSTI2019

New exact results for the two-phase model with several conserved currents

We consider the macroscopic transport properties of two-dimensional random binary mixtures with identical spatial distributions of the two phases. Previous studies have obtained exact analytical results for the electrical conductivity of a single layer with and without a magnetic field, as well as for the thermoelectric response of a magnetic field-free double-layer. Here, we generalize these exact solutions to the magneto-thermoelectric response of a single layer and to the thermoelectric response of a double-layer. The magneto-thermoelectric transport coefficients of the double-layer are calculated perturbatively for weak magnetic field.

77 NANOSCIENCE AND NANOTECHNOLOGY↗

DOE OSTI2018

Transient superconductivity without superconductivity

Recent experiments on K 3 C 60 and layered copper-oxide materials have reported substantial changes in the optical response following application of an intense THz pulse. These data have been interpreted as the stimulation of a transient superconducting state even at temperatures well above the equilibrium transition temperature. We propose an alternative phenomenology based on the assumption that the pulse creates a nonsuperconducting, though nonequilibrium, situation in which the linear response conductivity is negative. The negative conductivity implies that the spatially uniform prepulse state is unstable and evolves to a new state with a spontaneous electric polarization. Furthermore, this state exhibits coupled oscillations of entropy and electric charge whose coupling to incident probe radiation modifies the reflectivity, leading to an apparently superconductinglike response that resembles the data. Dependencies of the reflectivity on polarization and angle of incidence of the probe are predicted and other experimental consequences are discussed.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗