Theory for a quantum modulated transistor

Abstract

Articles you may be interested indc modulation in field-effect transistors operating under microwave irradiation for quantum readout J. Appl. Phys. 98, 044505 (2005); 10.1063/1.2007852 Microwave operation and modulation of a transistor laser Appl. Phys. Lett. 86, 131114 (2005); 10.1063/1.1889243Effect of signal modulated optical illumination on the Schrödinger wave function in a quantum well in a modulation doped field effect transistor and related device characteristics Resonant tunneling field-effect transistor based on wave function shape modulation in quantum wiresWe present a theoretical study of semiconductor T -structures which may exhibit transistor action based on quantum interference. The electron transmission through a semiconductor quantum wire can be controlled by an external gate voltage that modifies the penetration of the electron wavefunction in a lateral stub, affecting in this way its interference pattern. The structures are modeled as ideal two-dimensional electron waveguides and a tight-binding Green's function technique is used to compute the electron transmission and reflecti.on coefficients. The calculations show that relatively small changes in the stub length can induce strong variations in the electron transmission across the structure. Operation in the fundamental transverse mode appears to be important for applications. We also show that a bound state of purely geometrical origin nucleates at the intersection between waveguide and stub. The performance of the device can be improved by inserting additional stubs of slightly different lengths. Taking into account the applicable scaling rules, we give estimates of the experimental parameters that optimize the transmission characteristics and speed of operation ofthe proposed transistor. 3892

A single-mode quantum transport in serial-structure geometric scatterers

“…Such systems have been discussed recently [42] following earlier studies of a single-stub waveguide [37,43,44,47].…”

Modular recursive Green’s function method for ballistic quantum transport

“…However, in the semiclassical limit, mӷ1, D/dӷ1, the high number of large matrix inversions makes this method impractical. A hybrid method combining the RGM with the close-coupling approach has been recently proposed by Zozoulenko et al 26 In the following, we propose a variant of the RGM following an earlier suggestion by Sols et al 27,28 which appears suitable for extending quantum transport calculations to larger mode numbers towards the semiclassical regime. The underlying idea is to build up two-dimensional nonseparable open quantum dots out of simpler separable substructures.…”

Effect of potential fluctuations on shot noise suppression in mesoscopic cavities

“…Then, two adjacent sections are connected via a perturbation potentialV , and the overall Green's function is obtained using Dyson's equation. The recursive application of this procedure allows us to compute the Green's function of the whole structure, as well as, using a modified version 34 of the Fisher-Lee relation, 36, 37 the transmission matrix. Finally, from the transmission matrix, the conductance and shot noise power spectral density are obtained, within the Landauer-Büttiker formalism.…”

“…Transport and noise properties have been investigated using a recursive Green's function technique, 34,35 with a representation in real space in the longitudinal direction and over the transverse eigenmodes in the transverse direction. The device is subdivided into transverse slices: within each slice the potential is assumed to be longitudinally constant, and they are initially considered to be isolated and with Dirichlet boundary conditions at their ends.…”