On Field-Induced Quantum Criticality in YbRh_{2}Si_[2}

TL;DR

This paper investigates the quantum critical point in YbRh₂Si₂, proposing a model where a Mott transition in f-electrons explains the non-Fermi liquid behavior observed experimentally.

Contribution

It introduces an Extended Periodic Anderson Model within DMFT to explain the QCP via a selective Mott transition, offering a new perspective on heavy fermion quantum criticality.

Findings

Identifies a Fermi volume change near the QCP.

Explains non-Fermi liquid behavior at the QCP.

Links Mott transition to quantum criticality in YbRh₂Si₂.

Abstract

The quantum critical point (QCP) in $YbRh_{2}Si_{2}$ is an enigma for the itinerant view of QCP. In an alternative view, this QCP is intimately linked to the selective Mott localization of the heavy $f$ electrons. Following a perusal of this unusual QCP, I study an Extended Periodic Anderson Model (EPAM) within DMFT. A quantum phase transition (FQPT), accompanied by a rapid change in the Fermi volume, is found near the quantum-critical end-point of the selective Mott transition in the $f$-electron sector. The theory accounts for a wide range of unusual, singular non-Fermi liquid features exhibited at this QCP in $YbRh_{2}Si_{2}$ in a natural way.