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

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.

Anomaly in the temperature-dependent electronic structure of the heavy-fermion compound CeB6 : A theoretical investigation by means of a first-principles many-body approach

“…Fourth, no superconducting behavior and formation of spin (or charge) density wave for T > 10 K have been reported in the literatures until now. So these probabilities are ruled out 13 . Finally, we performed DFT + DMFT calculations for CeB 6 under ambient pressure.…”

“…Numerous theoretical and experimental investigations suggested that the electronic and magnetic structures of Ce-based heavy fermion compounds are very sensitive to the change of external environment, such as temperature, pressure, chemical doping, and electromagnetic field 13 . Here we focus on the temperature effect only.…”

First-order reversal curve of the magnetostructural phase transition in FeTe

“…For decades it was well-established wisdom that superconductors could not be magnetic, and could not even contain a substantial concentration of magnetic impurities. Yet beginning in the 1980's unconventional superconductors such as perovskites [1], 115s [2], and other heavy fermions [3] illustrated that in some cases magnetism could coexist with and even enable superconductivity. The trend culminated with the iron-based chalcogenides and pnictides, which claim among the highest superconducting transition temperatures of above 50 K despite containing the quintessential magnetic atom [4].…”

Structural and magnetic properties of antiferromagneticCe2IrGa12

“…Ce-based intermetallic compounds have attracted extensive interest owing to their exotic properties and fascinating underlying physics, such as complex magnetic order, unconventional superconductivity, and quantum criticality [1][2][3]. In these systems, the periodically arranged localized 4f moments are screened by the conduction electrons via the Kondo effect.…”