Electrical resistivity of heavy-fermion system of cubic YbCu5 under high pressures

Cubic YbCu5 with an AuBe5-type structure is one of the heaviest fermion systems in Yb-based compounds. In the Doniach diagram, its electronic state is in the vicinity of the quantum critical point. We examined the effects of pressure on the electrical resistivity rho of cubic YbCu5. It is found that there exists no evidence of magnetic ordering up to 2.9 GPa. The T-2 dependence of rho at the lowest temperature, which corresponds to a Fermi liquid, is preserved up to 2.9 GPa. With increasing pressure, the T-2 coefficient A increases, while the Kondo temperature T-K decreases; this suggests that the electronic state approaches the quantum critical point.