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F Marsiglio

Publications and source records attributed to F Marsiglio.

At least 19 recordsLinked to original sources
PubMed2006

Spin-Hall conductivity in electron-phonon coupled systems.

We derive the ac spin-Hall conductivity sigmasH(omega) of two-dimensional spin-orbit coupled systems interacting with dispersionless phonons of frequency omega0. For the linear Rashba model, we show that the electron-phonon contribution to the spin-vertex corrections breaks the universality of sigmasH(omega) at low frequencies and provides a nontrivial renormalization of the interband resonance. On the contrary, in a generalized Rashba model for which the spin-vertex contributions are absent, the coupling to the phonons enters only through the self-energy, leaving the low-frequency behavior of sigmasH(omega) unaffected by the electron-phonon interaction.

Journal Article↗
PubMed2001

Implications of reflectance measurements on the mechanism for superconductivity in MgB2.

Recent optical studies in c-axis oriented superconducting MgB2 films indicate that the electron-phonon coupling is weak. We reinforce this conclusion by examining the raw reflectance data; its frequency dependence is incompatible with strong electron-phonon scattering. This is further strengthened by analysis of the real part of the conductivity, and by the temperature dependence of the effective Drude scattering rate. Using a realistic electron-phonon spectral shape, we find lambda(tr) approximately 0.15. To the extent that lambda(tr) approximately lambda, this disagrees sharply with model calculations, and is far too low to provide the means for T(c) = 39 K. A simple model is constructed with coupling to a high frequency excitation, which is consistent with both the low frequency optical data and the high T(c).

Journal Article↗