Abstract
Discusses the effect of a magnetic field on the weak localisation of a two-dimensional electron gas. It is shown that due to quantum corrections the electron-electron relaxation time tau ee varies with electron temperature T and tau ee-1=A1T+A2T2, in the temperature range 3K-0.1K. This short tau ee causes a rapid transition between states which are weakly localised and so reduces the logarithmic correction to the conductance. Negative magnetoresistance measurements are reported for (100) silicon MOSFETs in the temperature range 0.1-4K.