Three-dimensional critical phase diagram of the Ising antiferromagnet CeRh$_2$Si$_2$ under intense magnetic field and pressure

TL;DR

This study maps the three-dimensional phase diagram of CeRh$_2$Si$_2$ under high magnetic field and pressure, revealing decoupled critical fields and quantum critical properties in a heavy-fermion antiferromagnet.

Contribution

It introduces a novel experimental approach combining high magnetic fields and pressure to explore the complex phase diagram of a heavy-fermion antiferromagnet.

Findings

Decoupling of critical and pseudo-metamagnetic fields with temperature and pressure.

Identification of quantum phase transitions and quantum critical properties.

Characterization of a class of heavy-fermion Ising antiferromagnets.

Abstract

Using novel instrumentation to combine extreme conditions of intense pulsed magnetic field up to 60~T and high pressure up to 4~GPa, we have established the three-dimensional (3D) magnetic field - pressure - temperature phase diagram of a pure stoichiometric heavy-fermion antiferromagnet (CeRh$_2$Si$_2$). We find a temperature- and pressure-dependent decoupling of the critical and pseudo-metamagnetic fields, at the borderlines of antiferromagnetism and strongly-correlated paramagnetism. This 3D phase diagram is representative of a class of heavy-fermion Ising antiferromagnets, where long-range magnetic ordering is decoupled from a maximum in the magnetic susceptibility. The combination of extreme conditions enabled us to characterize different quantum phase transitions, where peculiar quantum critical properties are revealed. The interest to couple the effects of magnetic field and pressure on quantum-critical correlated-electron systems is stressed.