← Back to search

Transition spectra for a BCS superconductor with multiple gaps: Model calculations for MgB2

Sergey V. Barabash, David Stroud

DOI 10.1103/PhysRevB.66.172501 · Physical Review B

T1

Active bibliographic source — not scientific approval

Bibliographic access preserves source history; it does not approve extracted materials or validate reported claims. Review warnings on each occurrence separately.

Abstract

We analyze the qualitative features in the transition spectra of a model superconductor with multiple energy gaps, using a simple extension of the Mattis-Bardeen expression for probes with case I and case II coherence factors. At temperature T=0, the far-infrared absorption edge is, as expected, determined by the smallest gap. However, the large thermal background may mask this edge at finite temperatures and instead the secondary absorption edges found at Δi+Δj may become most prominent. At finite T, if certain interband matrix elements are large, there may also be absorption peaks at the gap difference frequencies |Δi−Δj|/ħ. We discuss the effect of sample quality on the measured spectra and the possible relation of these predictions to the recent infrared absorption measurement on MgB2.

Source-reported materials — not catalogue approval

FormulaReported Tc (K)Pressure (GPa)Type
MgB2

Archive — visibility unverified

Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.

40Pressure not reportedunknown
MgB2

Archive — visibility unverified

Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.

30.5Pressure not reportedunknown

Similar papers