Exponential Temperature Dependence of Penetration Depth in MgB₂

2001/06/08 by F. Manzano, Manzano, F., A. Carrington +1
Physics and Astronomy · #FOS: Physical sciences #Physics of Superconductivity and Magnetism #Superconductivity (cond-mat.supr-con) #Superconductivity in MgB2 and Alloys #cond-mat.supr-con

paper · pdf · doi:10.48550/arxiv.cond-mat/0106166

4 pages - EPS figures included

arxiv created 2001/06/08 · openalex publication_date 2001/06/08 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

The temperature dependence of the London penetration depth, λ(T), was measured in polycrystalline MgB₂ samples by a high-resolution, radio frequency technique. A clear exponential temperature dependence of λ(T) was observed at low temperature, indicating s-wave pairing. A fit to the data gives an effective energy gap Δ of 2.8±0.4 meV (2Δ/k_BT_c=1.7±0.2), which is significantly smaller than the standard BCS weak coupling value of 3.5. This may be explained either by an anisotropic gap or the influence of low frequency phonon modes.

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