Critical behaviour of the Pauli spin susceptibility of strongly correlated electrons in two dimensions

Abstract

Thermodynamic measurements reveal that the Pauli spin susceptibility in a strongly correlated low-disorder two-dimensional electron system in silicon becomes enhanced by almost an order of magnitude at low electron densities and has a critical behaviour close to the metal--insulator transition point. This provides thermodynamic evidence for the existence of a phase transition. The nature of the low-density phase still remains unclear because it is masked by the residual disorder in the electron system.