DEHAAS-VANALPHEN AND SHUBNIKOV-DEHAAS OSCILLATIONS IN STRONGLY CORRELATED ELECTRON-GAS

We investigate the de Haas van Alphen (dHvA) and Shubnikov-de Haas (SdH) oscillations in a 2D strongly correlated electron system. The normal state is described by the fluxless phase (uniform RVB) of the t - J model. In the quantum limit, we find that conventional 2D dHvA sawtooth behavior is unattainable: in the limit near half-filling, where the magnetic energy dominates, one has square wave dHvA behavior with reduced amplitude; far from half-filling one finds a mixed square wave-sawtooth regime. The dHvA oscillation frequency is unchanged in all regimes, and it corresponds to Luttinger's Fermi surface. A conventional SdH effect exists in the above mentioned conventional regime, whereas it is absent in the square-wave dHvA regime. Lastly, it is shown that the linear-in-T contribution to the resistivity arising from chiral fluctuations in the fluxless phase dissappears in the presence of magnetic field in the quantum limit. We therefore predict that this strongly correlated metal shows a large negative magneto-resistance.