Transient magnetotransport through a quantum wire

Abstract

We consider an ideal parabolic quantum wire in a perpendicular magnetic field. A simple Gaussian shaped scattering potential well or hill is flashed softly on and off with its maximum at t = 0, mimicking a temporary broadening or narrowing of the wire. By an extension of the LippmannSchwinger formalism to time-dependent scattering potentials we investigate the effects on the continuous current that is driven through the quantum wire with a vanishingly small forward bias. The Lippmann-Schwinger approach to the scattering process enables us to investigate the interplay between geometrical effects and effects caused by the magnetic field.

Coulomb interaction and transient charging of excited states in open nanosystems

“…Figures 2͑a͒ and 2͑b͒ show the total currents in the left lead and the total charge residing in the sample for several values of the interaction strength. U is measured in units of The chemical potentials of the leads, L = 5.25 and R = 4.75, are chosen such that in the absence of Coulomb interaction, i.e., for U =0, 4 ͑0͒ is located within the bias window. In this case we obtain in the steady state the mean number of electrons about 3.6 and a nonvanishing current in the leads.…”

Time-dependent transport via the generalized master equation through a finite quantum wire with an embedded subsystem

“…We attempt to identify effects due to the underlying subband structure and also the formation of bound states due to the presence of the embedded potentials. Another motivation of this work is to compare the results of the present method with the ones obtained previously via the time-dependent Lippmann-Schwinger formalism [21,22]. Although one expects serious technical problems in the continuous model due to the large number of states and the quite complex form of the tunneling term we show here that one can actually say a lot about the time-dependent transport in extended systems by selecting a set of single particle states that are expected to be relevant for the transport process.…”

Site-dependent doping effects on quantum transport in zigzag graphene nanoribbons

“…A single impurity in quantum confined open systems can yield quasibound states below the subband bottoms which strongly backscatter the conduction electron at specific energy and reduce the quantized conductance [7][8][9][10]. Doping of GNRs to influence the electronic properties is an important aspect in GNR-based devices that can be achieved through techniques such as low energy ion implantation [11,12].…”

“…We explicitly examine the site-dependent doping effects on quantum transport in hydrogenated ZGNRs with a single B or N dopant located near their edges. The Coulomb interaction is taken into account to reexamine the quasibound state feature beyond the single-particle picture based on transverse invariance breaking [7][8][9]. Whereas the magnetic interaction strength in our sample is estimated to be less than 5 meV [20] or around 25 meV [21], we assume that the spin of conduction electrons is doubly degenerate [1] This article is organized as follows.…”