Search

We study the coherent exciton transport of continuous-time quantum walks (CTQWs) on Erdos–Renyi networks. We numerically investigate the transition probability between two nodes of the networks, and compare the classical and quantum transport efficiency on networks of different connectivity. In the long time limiting, we find that there is a high probability to find the exciton at the initial node. We also study how the network parameters affect such high return probability.

This paper shows that in YBCO and BSCCO there are five kinds of waves for the order parameter, d, pl, p2, s and extended s, and explains six important experimental facts.

We show that the anisotropic gap in the CuO 2 plane of high- T c cuprates is s ′ + i d ′, s ′ and d ′ being the extended s -wave and d -wave, respectively, and the maximum value of the gap is at the angle Φ = 12.2° at any fixed temperature, Φ being the angle from the CuO bond in the CuO 2 plane. Because the corresponding experimental maximum value is at Φ ⋍ 13° as well, it may be possible that the high T c in the cuprates is due mainly to the two-local-spin-mediated interaction.

From the numerical solution of the Eliashberg equation for more than a hundred model spectra of the Eliashberg function with single peak, it is concluded that the high T c superconductivity can in principle be caused by the phonon mechanism under the condition λ T c , the high frequency phonon is important and the low frequency phonon is negligible.

Using Abrikosov's pseudo-fermion method, Larsen's technique, and Cheung and Mattuck's procedures, this paper gives a new solution for exchange scattering with local spin S = 1 in dilute alloys, and show that the simple s-d model can solve the problem contradicting charge neutrality.

Using the Eliashberg equation in the Matsubara representation, the calculation of Tc for the PdH and PdD systems is performed under two schemes, and the inverse isotope effect is restudied. We conclude that the inverse isotope effect derives from the harmonicity of the lattice in most cases. In fact, there are more experiments to support our results.

Based on Weber's and Mattheiss's spectra, Frohlich's electron-phonon interaction and the Jahn-Teller effect, this paper concludes that the high Tc superconductivity of Ba2YCu3O7 originates in a phonon mechanism.