Volume 98, Number 1, April 2012
|Number of page(s)||6|
|Section||Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties|
|Published online||12 April 2012|
Proximity to valence transition in heavy fermion superconductor CeCu2Si2 under pressure
DPMC - Université de Genève - Quai Ernest Ansermet 24, 1211 Geneva 4, Switzerland
2 Centre de Physique Théorique, École Polytechnique, CNRS - 91128 Palaiseau Cedex, France, EU
3 Collège de France - 11 place Marcelin Berthelot, 75005 Paris, France, EU
Accepted: 14 March 2012
The first heavy fermion superconductor CeCu2Si2 is still only partially understood. At high pressures, superconductivity is supposed to be mediated by a different mechanism than at ambient pressure, where spin fluctuations most likely act as pairing glue. We have obtained and analyzed new resistivity data up to 7 GPa on a good quality CeCu2Si2 single crystal with an unprecedented high transition temperature. For the first time, we establish quantitatively that CeCu2Si2 lies in proximity to a valence transition: the critical end point could be located at 4.5±0.2 GPa and a slightly negative temperature, and the corresponding valence cross-over line has been added to the p-T phase diagram. This outcome is essential for the theoretically predicted critical valence fluctuations scenario, and opens new routes for further investigations in other Ce-based compounds.
PACS: 75.20.Hr – Local moment in compounds and alloys; Kondo effect, valence fluctuations, heavy fermions / 74.62.Fj – Effects of pressure / 74.25.fc – Electric and thermal conductivity
© EPLA, 2012
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.