YbRh(2)Si(2): pronounced non-fermi-liquid effects above a low-lyingmagnetic phase transition.
We report the first observation of non-Fermi-liquid (NFL) effects in a clean Yb compound at ambient pressure and zero magnetic field. The electrical resistivity and the specific-heat coefficient of high-quality single crystals of YbRh(2)Si(2) present a linear and a logarithmic temperature dependence, respectively, in more than a decade in temperature. We ascribe this NFL behavior to the presence of (presumably) quasi-2D antiferromagnetic spin fluctuations related to a very weak magnetic phase transition at T(N) approximately 65 mK. Application of hydrostatic pressure induces anomalies in the electrical resistivity, indicating the stabilization of magnetic order.
Trovarelli
O
O
Max-Planck Institute for Chemical Physics of Solids, D-01187 Dresden, Germany.
Geibel
C
C
Mederle
S
S
Langhammer
C
C
Grosche
F M
FM
Gegenwart
P
P
Lang
M
M
Sparn
G
G
Steglich
F
F