Electron-phonon or hole superconductivity in MgB2

J. E. Hirsch; F. Marsiglio

doi:10.1103/PhysRevB.64.144523

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Electron-phonon or hole superconductivity in MgB2

J. E. Hirsch, F. Marsiglio

DOI 10.1103/PhysRevB.64.144523 · Physical Review B

T1

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Abstract

The BCS electron-phonon mechanism and the unconventional “hole mechanism” have been proposed as explanations for the high-temperature superconductivity observed in MgB2. It is proposed that a critical test of which theory is correct is the dependence of Tc on hole doping: the hole mechanism predicts that Tc will drop rapidly to zero as holes are added, while the electron-phonon mechanism appears to predict increasing Tc for a substantial range of hole doping. Furthermore, the hole mechanism and electron-phonon mechanism differ qualitatively in their predictions of the effect on Tc of change in the B−B distances. We discuss predictions of the hole mechanism for a variety of observables as a function of doping, emphasizing the expected differences and similarities with the electron-phonon explanation. The hole mechanism predicts coherence length and penetration depth to increase and decrease monotonically with hole doping, respectively.

Source-reported materials — not catalogue approval

Formula	Reported Tc (K)	Pressure (GPa)	Type
MgB2 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	40	Pressure not reported	unknown