Search for E_2g phonon modes in MgB_2 single crystals by point-contact spectroscopy

Abstract

The electron-phonon interaction in magnesium diboride MgB_2 single crystals is investigated by point-contact (PC) spectroscopy. For the first time the electron coupling with E_2g phonon modes is resolved in the PC spectra. The correlation between intensity of the extremely broad E_2g modes in the PC spectra and value of the superconducting gap is established. Our observations favor current theoretical models for electron-phonon mediated superconductivity in MgB_2 and they better match the harmonic phonons model.

arXiv comment4 pages incl. 4 figs., RevTex4

References in corpus (23)

• Superconductivity of metallic boron in MgB_2
• Beyond Eliashberg superconductivity in MgB2: anharmonicity, two-phonon scattering, and multiple gaps
• Superconductivity of MgB2: Covalent Bonds Driven Metallic
• Electron-phonon interaction in the normal and superconducting states of MgB2
• Evidence for two superconducting energy gaps in MgB2 by point-contact spectroscopy
• Phonon dispersion and electron-phonon coupling in MgB_2 and AlB_2
• Giant anharmonicity and non-linear electron-phonon coupling in MgB${}_2$; A combined first-principles calculations and neutron scattering study
• First-Principles Calculation of the Superconducting Transition in MgB2 within the Anisotropic Eliashberg Formalism
• Two-Band Superconductivity in MgB2
• Specific heat of MgB${}_2$ in a one- and a two-band model from first-principles calculations
• Direct evidence for two-band superconductivity in MgB_2 single crystals from directional point-contact spectroscopy in magnetic fields
• Growth, structure analysis and anisotropic superconducting properties of MgB2 single crystals
• Phonon dispersion and lifetimes in MgB2
• Evidence for Two-Band Superconductivity from Break Junction Tunneling on MgB2
• Raman spectrum and lattice parameters of MgB2 as a function of pressure
• The Superconducting Gap in MgB_2: Electronic Raman Scattering Measurements of Single Crystals
• Phonons in MgB2 by Polarized Raman Scattering on Single Crystals
• The structure of the superconducting gap in MgB2 from point-contact spectroscopy
• Strong Coupling and Double Gap Density of States in Superconducting MgB2
• Electron-phonon interaction in transition metal diborides TB_2 (T=Zr, Nb, Ta) studied by point-contact spectroscopy
• Superconducting energy gap distribution in c-axis oriented MgB${}_2$ thin film from point contact study
• Phonon structure in I-V characteristic of MgB${}_2$ point-contacts
• MgB2: synthesis, sound velocity, and dynamics of the vortex phase

Cited by in corpus (8)

• Probing multiband superconductivity by point-contact spectroscopy
• Anharmonic phonon frequency shift in MgB2
• Can one extract the electron-phonon-interaction from tunneling data in case of the multigap superconductor MgB${}_2$?
• Advances in point-contact spectroscopy: two-band superconductor MgB2 (A review)
• Anharmonic theory of superconductivity and its applications to emerging quantum materials
• Theory of vortices in hybridized ballistic/diffusive-band superconductors
• Excess current in point contacts on two-band superconductor MgB${}_2$ in magnetic field
• Reconstruction of the electron-phonon interaction function in Ta, 2H-NbSe2 and MgB2 from spectra of S - c - N point-contacts