Quantum Phase Transition in the Itinerant Antiferromagnet (V0.9Ti0.1)2O3

TL;DR

This study investigates the quantum-critical behavior of (V0.9Ti0.1)2O3, revealing a T^{3/2} temperature dependence of spin fluctuations that confirms its proximity to a three-dimensional spin-density-wave quantum phase transition.

Contribution

First direct observation of antiferromagnetic spin fluctuations in (V0.9Ti0.1)2O3 using neutron scattering, demonstrating criticality of a 3D spin-density-wave quantum phase transition.

Findings

Spin fluctuations depend on temperature as c_1 + c_2 T^{3/2}.

The material exhibits quantum criticality consistent with a 3D SDW transition.

Confirmed the presence of quantum phase transition in a strongly correlated d-electron system.

Abstract

Quantum-critical behavior of the itinerant electron antiferromagnet (V0.9Ti0.1)2O3 has been studied by single-crystal neutron scattering. By directly observing antiferromagnetic spin fluctuations in the paramagnetic phase, we have shown that the characteristic energy depends on temperature as c_1 + c_2 T^{3/2}, where c_1 and c_2 are constants. This T^{3/2} dependence demonstrates that the present strongly correlated d-electron antiferromagnet clearly shows the criticality of the spin-density-wave quantum phase transition in three space dimensions.