Skip to content

Exponential Temperature Dependence of Penetration Depth in Single Crystal MgB2

F. Manzano, A. Carrington, N. E. Hussey, S. Lee, A. Yamamoto

cond-mat.supr-conarXiv:cond-mat/0110109

Abstract

The temperature dependence of the London penetration depth,lambda(T), was measured in both single crystal and polycrystalline MgB2 samples by a high-resolution, radio frequency technique. A clear exponential temperature dependence of lambda(T) was observed at low temperature, indicating s-wave pairing. A BCS fit to the lowest temperature data gives an in-plane energy gap Delta of 2.60.2 meV (2Δ/Tc=1.50.1), which is significantly smaller than the standard BCS weak coupling value of 3.5. We find that the data are best described by a two-gap model.

Create a lesson