Archivio Istituzionale della RicercaWe present the first results of directional point-contact spectroscopy in high-quality CaC_6 samples both along the ab plane and in the c-axis direction. The superconducting order parameter Delta(0), obtained by fitting the Andreev-reflection (AR) conductance curves at temperatures down to 400 mK with the single-band 3D Blonder-Tinkham-Klapwijk model, presents two different distributions in the two directions of the main current injection, peaked at 1.35 and 1.71 meV, respectively. By ab initio calculations of the AR conductance spectra, we show that the experimental results are in good agreement with the recent predictions of gap anisotropy in CaC_6.
Evidence for Gap Anisotropy in CaC6 from Directional Point-Contact Spectroscopy / Gonnelli, Renato; Daghero, Dario; Delaude, Debora; Tortello, Mauro; Ummarino, Giovanni; Stepanov, V. A; Kim, J. S; Kremer, R. K; Sanna, A; Profeta, G; Massidda, S.. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 100:(2008), pp. 207004-1-207004-4. [10.1103/PhysRevLett.100.207004]
Evidence for Gap Anisotropy in CaC6 from Directional Point-Contact Spectroscopy
GONNELLI, Renato;DAGHERO, Dario;DELAUDE, DEBORA;TORTELLO, MAURO;UMMARINO, Giovanni;
2008
Abstract
We present the first results of directional point-contact spectroscopy in high-quality CaC_6 samples both along the ab plane and in the c-axis direction. The superconducting order parameter Delta(0), obtained by fitting the Andreev-reflection (AR) conductance curves at temperatures down to 400 mK with the single-band 3D Blonder-Tinkham-Klapwijk model, presents two different distributions in the two directions of the main current injection, peaked at 1.35 and 1.71 meV, respectively. By ab initio calculations of the AR conductance spectra, we show that the experimental results are in good agreement with the recent predictions of gap anisotropy in CaC_6.
Pubblicazioni consigliate
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
https://hdl.handle.net/11583/1853709
Attenzione
Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo