Current flow past an etched barrier: field emission from a two-dimensional electron gasD. H. Cobden, G. Pilling, R. Parthasarathy, P. L. McEuen, I. M., E. H. Linfield, D. A. Ritchie and G. A. C. JonesEurophys. Lett., 41 3 (1998) 327-332DOI: https://doi.org/10.1209/epl/i1998-00151-4