摘要 |
A resonant tunneling structure for generating oscillation with multiple fundamental oscillation frequencies is provided. A first quantum well layer has a second sub-band (E2). A second quantum well layer has a first sub-band (E1) and a third sub-band (E3). When no electric field is applied, the resonant tunneling structure satisfies “(Eb1, Eb2)<E1<E2<E3”, where band edge energies of a first and second electrical contact layers relative to a carrier are expressed by Eb1 and Eb2, respectively. When a first electric field (Va) is applied, a resonant tunneling phenomenon is caused by the third sub-band and the second sub-band. When a second electric field (Vb) different in polarity from the first electric field is applied, a resonant tunneling phenomenon is caused by the second sub-band and the first sub-band.
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