Analysis of the ghost and mirror fields in the Nernst signal induced by superconducting fluctuations

A. Glatz; A. Pourret; A. A. Varlamov

doi:10.1103/PhysRevB.102.174507

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Analysis of the ghost and mirror fields in the Nernst signal induced by superconducting fluctuations

A. Glatz, A. Pourret, A. A. Varlamov

DOI 10.1103/PhysRevB.102.174507 · Physical Review B

T1

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Abstract

We present a complete analysis of the Nernst signal due to superconducting fluctuations in a large variety of superconductors from conventional to unconventional ones. A closed analytical expression of the fluctuation contribution to the Nernst signal is obtained in a large range of temperature and magnetic field. We apply this expression directly to experimental measurements of the Nernst signal in NbxSi1−x thin films and URu2Si2 superconductors. Both magnetic field and temperature dependence of the available data are fitted with very good accuracy using only two fitting parameters, the superconducting temperature Tc0 and the upper critical field Hc2(0). The obtained values agree very well with experimentally obtained values. We also extract the ghost lines (the maximum of the Nernst signal for constant temperature or magnetic field) from the complete expression and also compare it to several experimentally obtained curves. Our approach predicts a linear temperature dependence for the ghost critical field well above Tc0. Within the errors of the experimental data, this linearity is indeed observed in many superconductors far from Tc0.

Source-reported materials — not catalogue approval

Formula	Reported Tc (K)	Pressure (GPa)	Type
NbxSi1-x Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	—	Pressure not reported	unknown
URu2Si2 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	—	Pressure not reported	unknown
La1.8-xEux0.2SrxCuO4 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	—	Pressure not reported	unknown
Pr2-xCexCuO4 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	—	Pressure not reported	unknown