Compensation effect of one-dimensional disordered potential wells and barriers in the presence of an electric field

Abstract

We study the origin of the compensation in disordered mixed systems of the Wannier-Stark ladder effects observed previously as strong jumps of the transmission coefficient in ordered and disordered systems with potential wells and barriers subjected to a bias voltage. The one-dimensional Kronig-Penney model is used to investigate this problem by means of the transmission coefficient. We found that the band spectrum of the systems with barriers is shifted in comparison with the corresponding spectra of those with wells. Therefore the delocalization of each system in an electric field corresponds to the localization of the other. We found also that the disorder conserves the bandwidth of the ordered system if the average potential strength corresponds to the potential strength of this system.

Nonlinear interaction effect on the phase distribution in one-dimensional disordered lattices

“…In the case of mixed disorder (figures 1(a) and (b)) we notice that the PD is doubly peaked near π/2 and 3π/2 in the absence of nonlinearity, while in disordered barriers and wells, only a single peak appears near 3π/2 and π/2, respectively. Therefore the results obtained previously in this regime [4,9,10] cannot be extended to an arbitrary type of disorder and the superposition effect of these two types of disorder observed in the case of mixed disorder for the transmission properties [12] is also observed in the PD behaviour. In the presence of attractive (repulsive) NL potential, the peak at 3π/2 (π/2) disappears in the mixed disorder case, while the other peak is shifted towards π.…”

“…A strong discrepancy has been found recently [11] in the behaviour of the transmission between mixed disorder and disordered potential barriers (wells). The behaviour of the transmission in disordered potential barriers and wells has been shown to give rise to a compensation effect in the transmission in mixed disorder [12]. This compensation will certainly affect the behaviour of the PD.…”

Transverse electric field control of coherent quantum transport in a nanowire model

“…We follow [22], where the Krönig-Penney model with disorder is used to calculate the conductance. On the lines of [22,23], we note down the Krönig-Penney quantum model, introducing the potential (2):…”

“…A successful general theoretical description of all these properties can be found in [21]. We would also like to point out the paper [23] where the authors make use of a Krönig-Penney like model to evaluate the compensation effect of an external field on wave-function localization in a nanowire.…”

“…We believe that the consideration of nanowires requires more precise accounting for system geometry and overall model generalization in the presence of external fields and at a scale where coherent quantum transport plays an important role. In this paper we revise the nanowire model introduced in [23], and apply it to the description of a curved nanowire subjected to longitudinal acceleration and transverse controlling uniform electric fields. We perform a numerical analysis of the transverse electric field effect on charge transport in a onedimensional chain of scattering centers which represents a nanowire.…”