TY - JOUR

T1 - Coherence factors beyond the BCS result

AU - Gorohovsky, G.

AU - Bettelheim, E.

PY - 2013/8/26

Y1 - 2013/8/26

N2 - The dynamics of BCS (Bardeen-Cooper-Schrieffer) superconductors is fairly well understood due to the availability of a mean-field solution for the pairing Hamiltonian, a solution which gives the quantum state of a superconductor as a state of almost-free fermions interacting only with a condensate. As a result, transition probabilities may be computed, and expressed in terms of matrix elements of electron creation and annihilation operators between approximate eigenstates. These matrix elements are also called "coherence factors." Mean-field theory is however not sufficient to describe all eigenstates of a superconductor, a deficiency which is hardly important in (or very close to) equilibrium, but one that becomes relevant in certain out-of-equilibrium situations. We report here on a computation of matrix elements (coherence factors) for the pairing Hamiltonian between any "two-arc" eigenstates in the thermodynamic limit.

AB - The dynamics of BCS (Bardeen-Cooper-Schrieffer) superconductors is fairly well understood due to the availability of a mean-field solution for the pairing Hamiltonian, a solution which gives the quantum state of a superconductor as a state of almost-free fermions interacting only with a condensate. As a result, transition probabilities may be computed, and expressed in terms of matrix elements of electron creation and annihilation operators between approximate eigenstates. These matrix elements are also called "coherence factors." Mean-field theory is however not sufficient to describe all eigenstates of a superconductor, a deficiency which is hardly important in (or very close to) equilibrium, but one that becomes relevant in certain out-of-equilibrium situations. We report here on a computation of matrix elements (coherence factors) for the pairing Hamiltonian between any "two-arc" eigenstates in the thermodynamic limit.

UR - http://www.scopus.com/inward/record.url?scp=84883340092&partnerID=8YFLogxK

U2 - 10.1103/PhysRevB.88.060510

DO - 10.1103/PhysRevB.88.060510

M3 - Article

AN - SCOPUS:84883340092

SN - 1098-0121

VL - 88

JO - Physical Review B - Condensed Matter and Materials Physics

JF - Physical Review B - Condensed Matter and Materials Physics

IS - 6

M1 - 060510

ER -