ELECTRON-TUNNELING LIFETIME OF A QUASI-BOUND STATE IN A DOUBLE-BARRIER RESONANT-TUNNELING STRUCTURE

The level width of a quasibound state due to electron tunneling in a double-barrier resonant tunneling structure in an external electric field is investigated. The result for the width rests on the S-matrix resonant tunneling formalism. The inverse lifetime obtained in this manner is free of small parameter expansion and is exactly the width at the half-maximum of the resonant tunneling rate. It is found that for a system exhibiting current bistability, the level broadening of a quasibound state is not a monotonic function of the applied bias and has a minimum at some intermediate field strength.