We have studied the quantum transport phenomena in a double-barrier structure acted upon by a finite-range time-modulated potential. Inter-side-band mℏw transitions are made possible by the finiteness in the range of the oscillating field. For the case when the barrier width is small, such that the resonance state in between the barriers is too broadened, the dc conductance G exhibits peaks or dip structures when the chemical potential μ is at mℏw above the band bottom. For the case when the barrier width is large, such that the resonance state in between the barriers is well defined, the above feature is masked by resonant tunneling processes when μ is at energies mℏw away from the resonant energy Eb. In both cases, the dips or peaks in G are due to the temporary trapping of the transmitting electrons by the quasi-bound states. Furthermore, for the latter case, we also obtain the quenching of the resonant transmission found by Wagner, but with a small quantitative modification. Our calculation is nonperturbative which is valid for arbitrary potential strength and frequency. The form of the time-modulated potential is expected to be realized in a gate-induced potential configuration.
|Number of pages||10|
|Journal||Chinese Journal of Physics|
|State||Published - 1 Dec 1999|