Point-contact spectroscopy of MgB2

P. Samuely; P. Szabó; J. Kačmarčík; T. Klein; A. G.M. Jansen

doi:10.1016/S0921-4534(02)02344-4

Point-contact spectroscopy of MgB₂

P. Samuely, P. Szabó, J. Kačmarčík, T. Klein, A. G.M. Jansen

Research output: Contribution to journal › Article › peer-review

Abstract

Point-contact spectroscopy measurements on magnesium diboride reveal the existence of two superconducting energy gaps closing at the same transition temperature in line with the multi-band model of superconductivity. The sizes of the two gaps (Δ_π = 2.8 meV and Δ_σ = 6.5-7 meV) are respectively smaller and larger than the expected weak coupling value of the one-gap superconductor. The smaller gap is rapidly filled by a small magnetic field of about 1-2 T much lower than the real upper critical field H_c2. The larger gap is closed at the anisotropic H_c2. Above the gap energies reproducible non-linearities are observed at the characteristic phonon energies of MgB₂.

Original language	English
Pages (from-to)	244-254
Number of pages	11
Journal	Physica C: Superconductivity and its Applications
Volume	385
Issue number	1-2
DOIs	https://doi.org/10.1016/S0921-4534(02)02344-4
Publication status	Published - 1 Mar 2003
Externally published	Yes

Keywords

Multi-gap superconductivity
Phonons
Point contact tunneling spectroscopy
Upper critical field

Access to Document

10.1016/S0921-4534(02)02344-4

Cite this

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title = "Point-contact spectroscopy of MgB2 ",

abstract = "Point-contact spectroscopy measurements on magnesium diboride reveal the existence of two superconducting energy gaps closing at the same transition temperature in line with the multi-band model of superconductivity. The sizes of the two gaps (Δπ = 2.8 meV and Δσ = 6.5-7 meV) are respectively smaller and larger than the expected weak coupling value of the one-gap superconductor. The smaller gap is rapidly filled by a small magnetic field of about 1-2 T much lower than the real upper critical field Hc2. The larger gap is closed at the anisotropic Hc2. Above the gap energies reproducible non-linearities are observed at the characteristic phonon energies of MgB2.",

keywords = "Multi-gap superconductivity, Phonons, Point contact tunneling spectroscopy, Upper critical field",

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T1 - Point-contact spectroscopy of MgB2

AU - Samuely, P.

AU - Szabó, P.

AU - Kačmarčík, J.

AU - Klein, T.

AU - Jansen, A. G.M.

PY - 2003/3/1

Y1 - 2003/3/1

N2 - Point-contact spectroscopy measurements on magnesium diboride reveal the existence of two superconducting energy gaps closing at the same transition temperature in line with the multi-band model of superconductivity. The sizes of the two gaps (Δπ = 2.8 meV and Δσ = 6.5-7 meV) are respectively smaller and larger than the expected weak coupling value of the one-gap superconductor. The smaller gap is rapidly filled by a small magnetic field of about 1-2 T much lower than the real upper critical field Hc2. The larger gap is closed at the anisotropic Hc2. Above the gap energies reproducible non-linearities are observed at the characteristic phonon energies of MgB2.

AB - Point-contact spectroscopy measurements on magnesium diboride reveal the existence of two superconducting energy gaps closing at the same transition temperature in line with the multi-band model of superconductivity. The sizes of the two gaps (Δπ = 2.8 meV and Δσ = 6.5-7 meV) are respectively smaller and larger than the expected weak coupling value of the one-gap superconductor. The smaller gap is rapidly filled by a small magnetic field of about 1-2 T much lower than the real upper critical field Hc2. The larger gap is closed at the anisotropic Hc2. Above the gap energies reproducible non-linearities are observed at the characteristic phonon energies of MgB2.

KW - Multi-gap superconductivity

KW - Phonons

KW - Point contact tunneling spectroscopy

KW - Upper critical field

U2 - 10.1016/S0921-4534(02)02344-4

DO - 10.1016/S0921-4534(02)02344-4

M3 - Article

AN - SCOPUS:0037351166

SN - 0921-4534

VL - 385

SP - 244

EP - 254

JO - Physica C: Superconductivity and its Applications

JF - Physica C: Superconductivity and its Applications

IS - 1-2