High Field (H,T) Phase Diagram and Anisotropy of CeRhIn$_{5}$ single crystals

The specific heat ($C_{p})$ of a single crystal sample of composition CeRhIn$_{5}$ was measured as a function of temperature and magnetic field applied perpendicular and parallel to the crystallographic $c-$axis. Our experiments, carried out at temperatures below the AFM ordering temperature $T_{N}$ = 3.7 K, show a clear anomaly in $C_{p}(H)$ when the applied field is strong enough to suppress the magnetic order. This anomaly, which reduces the magnitude as the temperature is lowered, was used to map the ($H,T)$ phase diagram for the first time to a magnetic field of 55 T and temperatures as low as 700mK.\footnote{Y. Kohama, C. Marcenat, T. Klein, and M. Jaime, \textit{Rev. Sci. Instrum}., \textbf{81}, 104902 (2010).} Extrapolation of the low temperature phase boundary indicates the presence of a magnetic field-induced quantum critical point at $H_{c} \approx$ 50 T that is weakly dependent of the sample orientation, although intermediate magnetic fields reveal clear anisotropy. Our results will be discussed in the context of field-induced quantum phase transitions in strongly anisotropic correlated matter.