Quantum impurity model for two-stage multipolar ordering and Fermi surface reconstruction

TL;DR

This paper models quantum phase transitions in heavy fermion systems with multipolar moments, revealing two-stage ordering and Fermi surface changes driven by multipolar interactions and Kondo effects.

Contribution

It introduces an effective quantum impurity model capturing two-stage multipolar ordering and Fermi surface reconstruction in systems with complex local moments.

Findings

Two-stage multipolar ordering depends on participating moments.

Fermi surface reconstruction occurs at each quantum phase transition.

Kondo destruction influences decoupling of multipolar moments.

Abstract

Classification and understanding of quantum phase transitions and critical phenomena in itinerant electron systems are outstanding questions in quantum materials research. Recent experiments on heavy fermion systems with higher-rank multipolar local moments provide a new platform to study such questions. In particular, experiments on $\text{Ce}_{3}\text{Pd}_{20}\text{(Si,Ge)}_{6}$ show novel quantum critical behaviors via two consecutive magnetic field-driven quantum phase transitions. At each transition, the derivative of the Hall resistivity jumps discontinuously, which was attributed to sequential Fermi surface reconstructions. Motivated by this discovery, we consider an effective quantum impurity model of itinerant electrons coupled to local dipolar, quadrupolar, and octupolar moments arising from $\text{Ce}^{3+}$ ions. Using renormalization group analyses, we demonstrate that two-stage multipolar ordering and Fermi surface reconstruction arise depending on which multipolar moments participate in the Fermi surface and which other moments are decoupled via Kondo destruction.