Multiple quantum phase transitions and superconductivity in Ce-based heavy fermions

TL;DR

This paper reviews recent advances in Ce-based heavy fermion superconductors, focusing on multiple quantum phase transitions, their relation to electronic instabilities, and the evolution of Fermi surface topology near quantum critical points.

Contribution

It provides a comprehensive overview of multiple quantum critical points and their classification in Ce-based heavy fermion systems, highlighting the connection to superconductivity and electronic instabilities.

Findings

Multiple quantum critical points can be classified by Fermi surface topology changes.

Superconductivity emerges near magnetic and charge instabilities.

Quantum criticality plays a key role in heavy fermion properties.

Abstract

Heavy fermions have served as prototype examples of strongly-correlated electron systems. The occurrence of unconventional superconductivity in close proximity to the electronic instabilities associated with various degrees of freedom points to an intricate relationship between superconductivity and other electronic states, which is unique but also shares some common features with high temperature superconductivity. The magnetic order in heavy fermion compounds can be continuously suppressed by tuning external parameters to a quantum critical point, and the role of quantum criticality in determining the properties of heavy fermion systems is an important unresolved issue. Here we review the recent progress of studies on Ce based heavy fermion superconductors, with an emphasis on the superconductivity emerging on the edge of magnetic and charge instabilities as well as the quantum phase transitions which occur by tuning different parameters, such as pressure, magnetic field and doping. We discuss systems where multiple quantum critical points occur and whether they can be classified in a unified manner, in particular in terms of the evolution of the Fermi surface topology.