Pressure versus Magnetic-Field Tuning of a Magnetic Quantum Phase Transition

Specific heat C(T) and electrical resistivity $̊ho$(T) of CeCu6-xAux at very low temperatures T show distinctly different behavior depending on whether long-range antiferromagnetic order is suppressed by hydrostatic pressure p or an applied magnetic field B. p tuning yields C/T=aln(T0/T) and $̊ho\approx̊ho$0+A$′$T, while B tuning shows C/T=$\gamma$0-a$′$T0.5 and $̊ho\approx̊ho$0+A''T1.5. This suggests that the spectrum of low-lying excitations that determines the behavior near these quantum phase transitions differs.     «

Specific heat C(T) and electrical resistivity $̊ho$(T) of CeCu6-xAux at very low temperatures T show distinctly different behavior depending on whether long-range antiferromagnetic order is suppressed by hydrostatic pressure p or an applied magnetic field B. p tuning yields C/T=aln(T0/T) and $̊ho\approx̊ho$0+A$′$T, while B tuning shows C/T=$\gamma$0-a$′$T0.5 and $̊ho\approx̊ho$0+A''T1.5. This suggests that the spectrum of low-lying excitations that determines the behavior near these quantum phas...     »