Towards the identification of a quantum critical line in the (p, B) phase diagram of CeCoIn5

Abstract

The low-temperature thermal expansion of CeCoIn5 single crystals measured parallel and perpendicular to magnetic fields B oriented along the c axis yields the volume thermal-expansion coefficient $\beta$. Considerable deviations of $\beta (T)$ from Fermi-liquid behavior occur already within the superconducting region of the (B, T) phase diagram and become maximal at the upper critical field $B_{c2}^0$. However, $\beta (T)$ and the Grüneisen parameter $\Gamma$ are incompatible with a quantum critical point (QCP) at $B_{c2}^0$, but allow for a QCP shielded by superconductivity and extending to negative pressures for $B<B_{c2}^0$. Together with literature data we construct a tentative (p, B, T) phase diagram of CeCoIn5 suggesting a quantum critical line in the (p, B) plane.

4 pages, 3 figures

References in corpus (7)

• Fermi-liquid instabilities at magnetic quantum phase transitions
• Reversible Tuning of the Heavy Fermion Ground State in CeCoIn${}_5$
• Fulde-Ferrell-Larkin-Ovchinnikov state in a perpendicular field of quasi two-dimensional CeCoIn5
• Nonvanishing Energy Scales at the Quantum Critical Point of CeCoIn5
• Pressure Study of Quantum Criticality in CeCoIn5
• Dimensional crossover of quantum critical behavior in CeCoIn${}_5$
• Anisotropic effect of Cd and Hg doping on Pauli limited superconductor CeCoIn${}_5$