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Directional point-contact spectroscopy of MgB$_{2}$ single crystals in magnetic fields: two-band superconductivity and critical fields
The results of the first directional point-contact measurements in MgB2 single crystals, in the presence of magnetic fields up to 9 T either parallel or perpendicular to the ab planes, are presented. By applying suitable magnetic fields, we separated the partial contributions of the sigma and pi ban...
| Autores principales: | , , , , , , , , |
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| Lenguaje: | eng |
| Publicado: |
2003
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| Materias: | |
| Acceso en línea: | http://cds.cern.ch/record/618086 |
| _version_ | 1780900317849714688 |
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| author | Gonnelli, R S Daghero, D Ummarino, G A Della Rocca, V Calzolari, A Stepanov, V A Jun, J Kazakov, S M Karpinski, J |
| author_facet | Gonnelli, R S Daghero, D Ummarino, G A Della Rocca, V Calzolari, A Stepanov, V A Jun, J Kazakov, S M Karpinski, J |
| author_sort | Gonnelli, R S |
| collection | CERN |
| description | The results of the first directional point-contact measurements in MgB2 single crystals, in the presence of magnetic fields up to 9 T either parallel or perpendicular to the ab planes, are presented. By applying suitable magnetic fields, we separated the partial contributions of the sigma and pi bands to the total Andreev-reflection conductance. Their fit with the BTK model allowed a very accurate determination of the temperature dependency of the gaps (Delta_sigma and Delta_pi), that resulted in close agreement with the predictions of the two-band models for MgB2. We also obtained, for the first time with point-contact spectroscopy, the temperature dependence of the (anisotropic) upper critical field of the sigma band and of the (isotropic) upper critical field of the pi band. |
| id | cern-618086 |
| institution | Organización Europea para la Investigación Nuclear |
| language | eng |
| publishDate | 2003 |
| record_format | invenio |
| spelling | cern-6180862019-09-30T06:29:59Zhttp://cds.cern.ch/record/618086engGonnelli, R SDaghero, DUmmarino, G ADella Rocca, VCalzolari, AStepanov, V AJun, JKazakov, S MKarpinski, JDirectional point-contact spectroscopy of MgB$_{2}$ single crystals in magnetic fields: two-band superconductivity and critical fieldsCondensed MatterThe results of the first directional point-contact measurements in MgB2 single crystals, in the presence of magnetic fields up to 9 T either parallel or perpendicular to the ab planes, are presented. By applying suitable magnetic fields, we separated the partial contributions of the sigma and pi bands to the total Andreev-reflection conductance. Their fit with the BTK model allowed a very accurate determination of the temperature dependency of the gaps (Delta_sigma and Delta_pi), that resulted in close agreement with the predictions of the two-band models for MgB2. We also obtained, for the first time with point-contact spectroscopy, the temperature dependence of the (anisotropic) upper critical field of the sigma band and of the (isotropic) upper critical field of the pi band.cond-mat/0305560oai:cds.cern.ch:6180862003-05-23 |
| spellingShingle | Condensed Matter Gonnelli, R S Daghero, D Ummarino, G A Della Rocca, V Calzolari, A Stepanov, V A Jun, J Kazakov, S M Karpinski, J Directional point-contact spectroscopy of MgB$_{2}$ single crystals in magnetic fields: two-band superconductivity and critical fields |
| title | Directional point-contact spectroscopy of MgB$_{2}$ single crystals in magnetic fields: two-band superconductivity and critical fields |
| title_full | Directional point-contact spectroscopy of MgB$_{2}$ single crystals in magnetic fields: two-band superconductivity and critical fields |
| title_fullStr | Directional point-contact spectroscopy of MgB$_{2}$ single crystals in magnetic fields: two-band superconductivity and critical fields |
| title_full_unstemmed | Directional point-contact spectroscopy of MgB$_{2}$ single crystals in magnetic fields: two-band superconductivity and critical fields |
| title_short | Directional point-contact spectroscopy of MgB$_{2}$ single crystals in magnetic fields: two-band superconductivity and critical fields |
| title_sort | directional point-contact spectroscopy of mgb$_{2}$ single crystals in magnetic fields: two-band superconductivity and critical fields |
| topic | Condensed Matter |
| url | http://cds.cern.ch/record/618086 |
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