Electronic structure near quantum critical point

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.