Selective manipulation of the emission spectrum of an electron in a biased double-well heterostructure driven by a free-electron laser

We study the emission spectrum of an electron in a biased double-well heterostructure driven by a cw laser field. It is shown that, in general, the emission spectrum consists of triplets at all harmonics of the laser frequency. We analytically and numerically show that it is possible, by making the proper choice of parameters, to selectively eliminate each line in the spectrum.