Patent ID: 7924107

Claim:
A resonant tunneling structure, comprising: a resonant tunneling structure layer including at least three tunnel barrier layers; and a first electrical contact layer and a second electrical contact layer each having a carrier, wherein the first electrical contact layer, the resonant tunneling structure layer and the second electrical contact layer are arranged in this order, wherein the resonant tunneling structure layer includes a first sub-band, a second sub-band, and a third sub-band which respectively have energies E 1 , E 2 , and E 3 relative to the carrier, and wherein the resonant tunneling structure is such that where band edge energies of the first and second electrical contact layers relative to the carrier are expressed by E b1 and E b2 , respectively, when no electric field is applied to the resonant tunneling structure, (E b1 , E b2 )<E 1 <E 2 <E 3 is satisfied; when a first electric field is applied to the resonant tunneling structure, the third sub-band and the second sub-band resonate with each other between the energy E b1 and a near Fermi level energy of the first electrical contact layer; and when a second electric field different in polarity from the first electric field is applied to the resonant tunneling structure, the second sub-band and the first sub-band resonate with each other between the energy E b2 and a near Fermi level energy of the second electrical contact layer.