Superconducting Sweet-Spot in Microcrystalline Graphite Revealed by Point-Contact Spectroscopy. / Arnold, Frank; Nyeki, Jan; Saunders, John.

In: JETP LETTERS, Vol. 107, No. 9, 02.05.2018, p. 577-578.

Research output: Contribution to journalLetterpeer-review

E-pub ahead of print



In this letter we describe the observation of a magnetic field dependent electronic gap, suggestive of local superconductivity, in the point-contact spectrum of microcrystalline graphite. Magnetic field dependent point-contact spectroscopy was carried out at a temperature of 1.8K using an etched aluminium tip. At zero field a gap structure in the differential conductance is observed, showing a gap of Δ = 4.2meV. On applying magnetic fields of up to 500mT, this gap gradually closes, following the theoretical prediction by Ginzburg and Landau for a fully flux-penetrated superconductor. By applying BCS-theory, we infer a critical
superconducting temperature of 14K.
Original languageEnglish
Pages (from-to)577-578
Number of pages2
Issue number9
Publication statusE-pub ahead of print - 2 May 2018
This open access research output is licenced under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.

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