An exact numerical calculation for an isolated quantum well of a GaAs-GaAlAs system subjected to an external electric field is presented. Resonance positions and widths, and density-of-states profiles are reported for a 30-Å well to demonstrate that the rigorous description of the high-field states as resonances leads to qualitatively new phenomena. In particular, in fields of 4×${10}^5$ V ${\mathrm{cm}}^{-1\mathrm{}}$ the effective hole energy shift is reduced to zero and a new antiresonance state emerges from the continuum into the well.

• Received 4 February 1985

DOI:https://doi.org/10.1103/PhysRevB.31.5569