hide
Free keywords:
quantum phase transition; heavy-fermion systems
Abstract:
The low temperature properties of CeCu6-xAux show different behavior at the quantum phase transition depending on how the long-range antiferromagnetic order is suppressed. Tuning by hydrostatic pressure p results in a temperature dependence of the specific heat C(T) and the electrical resistivity rho(T) as C/T = a ln(T-0/T) and rho approximate to rho(0) + A'T, while C/T = gamma(0) - a'T-0.5 and rho approximate to rho(0) + A"T- 1.5 when tuned by applying a magnetic field B. The magnetic (p, T) and (B, T) phase diagrams as inferred from specific heat, electrical resistivity and neutron diffraction measurements are distinctly different. These findings suggest that the spectra of the low-lying magnetic fluctuations near these quantum phase transitions differ. (C) 2002 Elsevier Science B.V. All rights reserved.
