Anomalous change in the field dependence of the electronic specific heat of an electron-doped cuprate superconductor.
We present specific heat measurements on Pr(2-x)CexCuO(4-delta) single crystals which show an unexpected change in the field dependence of the electronic specific heat (Cel) from linear at T = 2 K to nonlinear at T > or = 3 K. We consider several possible explanations for this change and propose, as a possible interpretation, a phase transition in the symmetry of the order parameter from nodal (e.g., d wave) at T > or = 3 K to gapped (e.g., s wave) at T = 2 K. Such a phase transition could be an explanation for the previous conflicting experimental results on the pairing symmetry in the electron-doped cuprates.
Center for Superconductivity Research, Department of Physics, University of Maryland, College Park 20742, USA.
Hamza
H
Balci
R L
RL
Greene