Field-Induced Quantum Critical Point in CeCoIn5
Abstract
The resistivity of the heavy-fermion superconductor CeCoIn5 was measured as a function of temperature, down to 25mK and in magnetic fields of up to 16T applied perpendicular to the basal plane. With increasing field, we observe a suppression of the non-Fermi liquid behavior, ρ∼T, and the development of a Fermi liquid state, with its characteristic ρ=ρ0+AT2 dependence. The field dependence of the T2 coefficient shows critical behavior with an exponent of 1.37. This is evidence for a field-induced quantum critical point (QCP), occurring at a critical field which coincides, within experimental accuracy, with the superconducting critical field Hc2. We discuss the relation of this field-tuned QCP to a change in the magnetic state, seen as a change in magnetoresistance from positive to negative, at a crossover line that has a common border with the superconducting region below ∼1 K.
- Publication:
-
Physical Review Letters
- Pub Date:
- December 2003
- DOI:
- 10.1103/PhysRevLett.91.246405
- arXiv:
- arXiv:cond-mat/0212502
- Bibcode:
- 2003PhRvL..91x6405P
- Keywords:
-
- 71.27.+a;
- 73.43.Qt;
- 75.40.-s;
- Strongly correlated electron systems;
- heavy fermions;
- Magnetoresistance;
- Critical-point effects specific heats short-range order;
- Condensed Matter - Superconductivity;
- Condensed Matter - Strongly Correlated Electrons
- E-Print:
- 4 pages, 3 figures (published version)