Emergence of coherent transport in UBe13: an optical investigation in both the normal and superconducting states.
The far-infrared reflectance of heavy-fermion superconductor UBe13 has been measured from 0.5 K in the superconducting state, to 300 K. Coherent transport, characterized by an optical conductivity that exhibits a renormalized Drude peak at low frequencies, emerges between 45 and 85 K although the dc resistivity of UBe13 continues to increase with decreasing temperature down to approximately 2.5 K. In the superconducting state, the low frequency scattering rate falls abruptly, implying that the formation of the condensate alters dramatically the interaction between the heavy electrons.
Holden
A A Brown
AA
Department of Physics, Brock University, St. Catharines, Ontario, Canada L2S 3A1.
Wardlaw
G M
GM
Reedyk
M
M
Smith
J L
JL