General properties of phase diagrams of heavy-fermion metals

TL;DR

This paper investigates the phase diagrams of heavy-fermion metals, revealing a universal linear B-dependence of the crossover temperature T*(B) at high temperatures, linked to fermion condensation quantum phase transition, consistent with experimental data.

Contribution

It demonstrates the universal linear B-dependence of T*(B) in heavy-fermion metals due to fermion condensation quantum phase transition, supported by experimental and magnetization data.

Findings

T*(B) follows a linear B-dependence crossing the origin.

Universal temperature behavior of dM/dT over magnetic field scaling.

Good agreement with experimental phase diagrams of specific heavy-fermion metals.

Abstract

We study the temperature-magnetic field T-B phase diagrams of heavy fermion (HF) metals, and show that at sufficiently high temperatures outside the ordered phase the crossover temperature T*(B), regarded as the energy scale, follows a linear B-dependence, crossing the origin of the T-B phase diagram. This behavior of T*(B) constitutes the general property, and is formed by the presence of fermion condensation quantum phase transition hidden within the ordered phase. Our result is in good agreement with the experimental T-B phase diagram of the HF metals YbRh2Si2, Yb(Rh{0.93}Co{0.07})2Si2, and Yb(Rh{0.94}Ir{0.06})2Si2. To support our observations, we analyze the isothermal magnetization M, and demonstrate that dM/dT exhibits a universal temperature behavior over magnetic field scaling. The obtained results are in good agreement with the corresponding data collected on YbRh2Si2 as a function of magnetic field at different temperatures under hydrostatic pressure.