Five different modes of high-field domains due to field-dependent carrier diffusion

Five different modes of high-field domains due to the field-dependent diffusion coefficient in a material with negative differential mobility (NDM) are discussed. Two of them are periodically traveling domain modes whose traveling directions are opposite each other. The remainder are trapped domain modes and are classified by the positions where the domains are trapped. For a bulk-effect device operated in the trapped domain mode, the static negative resistance (SNR) appears in its current-voltage characteristic.