Cluster dynamical mean field methods are used to calculate the normal and anomalous components of the electron self-energy of the two-dimensional Hubbard model. Issues associated with the analytical continuation of the normal and anomalous parts of the gap function are discussed. Methods of minimizing the uncertainties associated with the pseudogap-related pole in the self-energy are discussed. From these the evolution of the superconducting gap and the momentum-dependent electron spectral function across the phase diagram are determined. In the pseudogap regime, decreasing the temperature into the superconducting state leads to a decrease in the energy gap and the formation of a ``peak-dip-hump'' structure in the electronic density of states. The peak feature disperses very weakly. The calculated spectral functions are in good qualitative agreement with published data. The mathematical origin of the behavior is found to be the effect of the superconductivity on the pole structure giving rise to the normal state pseudogap. In particular the ``hump'' feature is found to arise from a zero crossing of the real part of the electron self-energy rather than from an onset of scattering. The effect of superconductivity on the zone diagonal spectra is presented.Cluster dynamical mean field methods are used to calculate the normal and anomalous components of the electron self-energy of the two-dimensional Hubbard model. Issues associated with the analytical continuation of the normal and anomalous parts of the gap function are discussed. Methods of minimizing the uncertainties associated with the pseudogap-related pole in the self-energy are discussed. From these the evolution of the superconducting gap and the momentum-dependent electron spectral function across the phase diagram are determined. In the pseudogap regime, decreasing the temperature into the superconducting state leads to a decrease in the energy gap and the formation of a ``peak-dip-hump'' structure in the electronic density of states. The peak feature disperses very weakly. The calculated spectral functions are in good qualitative agreement with published data. The mathematical origin of the behavior is found to be the effect of the superconductivity on the pole structure giving rise to the normal state pseudogap. In particular the ``hump'' feature is found to arise from a zero crossing of the real part of the electron self-energy rather than from an onset of scattering. The effect of superconductivity on the zone diagonal spectra is presented.

arXiv:1412.5031Physical Review BFeb 20, 201545 citations

Superconducting Digital Electronics – An overview

Pascal Febvre

Mar 14, 20180 citations

Tunneling and superconductivity of strongly repulsive electrons

Frédéric Mila, Elihu Abrahams

We show that superconductive pairing is possible in the presence of an arbitrarily strong short-range repulsion between electrons if the gap is an odd function of k- ${\mathit{k}}_{\mathit{F}}$ . We discuss how the behavior of \ensuremath{\Delta}(k- ${\mathit{k}}_{\mathit{F}}$ ) close to the Fermi surface is related to (i) the low-energy tunneling density of states, and (ii) the attractive part of the potential. We show that some features of the tunneling data in high- ${\mathit{T}}_{\mathit{c}}$ cuprates, including the fact that the maximum hardly moves when T approaches ${\mathit{T}}_{\mathit{c}}$ , are natural consequences of this type of pairing.We show that superconductive pairing is possible in the presence of an arbitrarily strong short-range repulsion between electrons if the gap is an odd function of k-${\mathit{k}}_{\mathit{F}}$. We discuss how the behavior of \ensuremath{\Delta}(k-${\mathit{k}}_{\mathit{F}}$) close to the Fermi surface is related to (i) the low-energy tunneling density of states, and (ii) the attractive part of the potential. We show that some features of the tunneling data in high-${\mathit{T}}_{\mathit{c}}$ cuprates, including the fact that the maximum hardly moves when T approaches ${\mathit{T}}_{\mathit{c}}$, are natural consequences of this type of pairing.

Physical Review LettersOct 1, 199131 citations

Superconducting electronics

Aleksander I. Braginski

Physics TodayJul 1, 19831 citation

We show that superconductive pairing is possible in the presence of an arbitrarily strong short-range repulsion between electrons if the gap is an odd function of k-

{\mathit{k}}_{\mathit{F}}

. We discuss how the behavior of \ensuremath{\Delta}(k-

{\mathit{k}}_{\mathit{F}}

) close to the Fermi surface is related to (i) the low-energy tunneling density of states, and (ii) the attractive part of the potential. We show that some features of the tunneling data in high-

{\mathit{T}}_{\mathit{c}}

cuprates, including the fact that the maximum hardly moves when T approaches

{\mathit{T}}_{\mathit{c}}

, are natural consequences of this type of pairing.