Pressure studies of the quantum critical alloy Ce(0.93)Yb(0.07)CoIn5

TL;DR

This study investigates how pressure affects the transport properties of a Yb-doped heavy-fermion alloy near a quantum critical point, revealing suppression of quantum fluctuations and insights into quasiparticle scattering.

Contribution

It provides a combined experimental and theoretical analysis of pressure effects on a specific heavy-fermion alloy near quantum criticality, using the coherent potential approximation.

Findings

Pressure suppresses quantum fluctuations similar to the parent compound.

The square-root temperature resistivity component is pressure-insensitive.

Coherence temperature increases and residual resistivity decreases with pressure.

Abstract

Here we present our experimental and theoretical study of the effects of pressure on the transport properties of the heavy-fermion alloy Ce(1-x)Yb(x)CoIn5 with x~0.07. We specifically choose this value of ytterbium concentration because the magnetic-field-induced quantum critical point, which separates the antiferromagnetic and paramagnetic states at zero temperature, approaches zero, as has been established in previous studies. Our measurements show that pressure further suppresses quantum fluctuations in this alloy, just as it does in the parent compound CeCoIn5. In contrast, the square-root temperature dependent part of resistivity remains insensitive to pressure, indicating that the heavy-quasiparticles are not involved in the scattering processes leading to such a temperature dependent resistivity. We demonstrate that the growth of the coherence temperature with pressure, as well as the decrease of the residual resistivity, can be accurately described by employing the coherent potential approximation for a disordered Kondo lattice.