Field-induced quantum critical point in CeCoIn5

The resistivity of CeCoIn5 was measured down to 20 mK in magnetic fields of up to 16 T. With increasing field, we observe a suppression of the non-Fermi liquid behavior, rhoT, and the development of a Fermi liquid state, with its characteristic rho=rho0+AT2 dependence. The field dependence of the T2 coefficient shows critical behavior with an exponent of 4/3. This is evidence for a new field-induced quantum critical point, occurring in this case at a critical field which coincides with the superconducting upper critical field Hc2.