Field-angle-dependent specific heat measurements and gap determination of a heavy fermion superconductor URu2Si2.
To identify the superconducting gap structure in URu2Si2, we perform field-angle-dependent specific heat measurements for the two principal orientations in addition to field rotations, and a theoretical analysis based on microscopic calculations. The Sommerfeld coefficient gamma(H)'s in the mixed state exhibit a distinctly different field dependence. This comes from point nodes and the substantial Pauli paramagnetic effect of URu2Si2. These two features combined give rise to a consistent picture of superconducting properties, including a possible first order transition of Hc2 at low temperatures.
Yano
K
K
Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 270-8581, Japan.
Sakakibara
T
T
Tayama
T
T
Yokoyama
M
M
Amitsuka
H
H
Homma
Y
Y
Miranović
P
P
Ichioka
M
M
Tsutsumi
Y
Y
Machida
K
K