Quenching of the 2D Metallic State by Aligning the Electron Spins

We discuss the destabilisation of the electron 2D metallic state by an in-plane magnetic field. We demonstrate that such a field can destabilise the metallic state through spin polarisation which significantly enhances the exchange correlations between electrons. We find that the conducting phase of the fully spin polarised system is almost completely suppressed. We discuss this phenomenon within a memory function formalism which treats both disorder and exchange-correlation effects. We determine the shift in the position of the metal–insulator phase boundary as the system is polarised by an increasing parallel magnetic field.