Electronic structure near quantum critical point

TL;DR

This study investigates the electronic structure evolution near a quantum critical point in V-doped Cr, revealing pseudogap and Kondo resonance features that persist at criticality, indicating non-Fermi liquid behavior in correlated electron systems.

Contribution

It provides experimental evidence of pseudogap and orbital Kondo resonance near a quantum critical point in V-doped Cr, highlighting their relevance in quantum phases of correlated electrons.

Findings

Pseudogap and Kondo resonance signatures are observed at low temperatures across compositions.

These features decrease with V doping but remain finite at the quantum critical point.

Spectral lineshape shows (E_F - E)^{0.25} dependence, indicating non-Fermi liquid behavior.

Abstract

We studied the evolution of the electronic structure across the quantum critical point in V doped Cr employing high resolution photoemission spectroscopy. Experimental results exhibit signatures of pseudogap and orbital Kondo resonance peak at low temperatures for all the compositions studied suggesting a scenario of spin density wave quantum criticality corresponding to orbital Kondo effect. The pseudogap and the Kondo peak gradually reduces with V doping but remains finite at the quantum critical point indicating their relevance in widely discussed quantum phases in correlated electron systems. The spectral lineshape near the Fermi level exhibit (E_F - E)^{0.25} dependence evidencing deviation from Fermi liquid behavior.