SPONTANEOUS DC CURRENT GENERATION IN A RESISTIVELY SHUNTED SEMICONDUCTOR SUPERLATTICE DRIVEN BY A TERAHERTZ FIELD

We study a resistively shunted semiconductor superlattice subject to a high-frequency electric field. Using a balance equation approach that incorporates the influence of the electric circuit, we determine nume rically a range of amplitude and frequency of the ac field for which a de bias and current are generated spontaneously and show that this re gion is likely accessible to current experiments. Our simulations reve al that the Bloch frequency corresponding to the spontaneous de bias i s approximately an integer multiple of the ac field frequency.