0103029v1

related topics
{equation, function, exp}
{wave, scattering, interference}
{let, theorem, proof}
{force, casimir, field}
{state, algorithm, problem}
{vol, operators, histories}
{qubit, qubits, gate}
{energy, gaussian, time}
{cavity, atom, atoms}
{cos, sin, state}

Scattering in quantum tubes

B. Nilsson

abstract: It is possible to fabricate mesoscopic structures where at least one of the dimensions is of the order of de Broglie wavelength for cold electrons. By using semiconductors, composed of more than one material combined with a metal slip-gate, two-dimensional quantum tubes may be built. We present a method for predicting the transmission of low-temperature electrons in such a tube. This problem is mathematically related to the transmission of acoustic or electromagnetic waves in a two-dimensional duct. The tube is asymptotically straight with a constant cross-section. Propagation properties for complicated tubes can be synthesised from corresponding results for more simple tubes by the so-called Building Block Method. Conformal mapping techniques are then applied to transform the simple tube with curvature and varying cross-section to a straight, constant cross-section, tube with variable refractive index. Stable formulations for the scattering operators in terms of ordinary differential equations are formulated by wave splitting using an invariant imbedding technique. The mathematical framework is also generalised to handle tubes with edges, which are of large technical interest. The numerical method consists of using a standard MATLAB ordinary differential equation solver for the truncated reflection and transmission matrices in a Fourier sine basis. It is proved that the numerical scheme converges with increasing truncation.

oai_identifier:
oai:arXiv.org:quant-ph/0103029
categories:
quant-ph
comments:
10 pages, 4 figures
arxiv_id:
quant-ph/0103029
created:
2001-03-07

Full article ▸

related documents
0204053v1
0411113v1
0006019v1
0406019v1
0012039v1
0406167v2
0210120v2
0410181v1
0507239v1
0701227v2
9808016v1
0208055v3
9903002v1
0104079v1
0011062v3
0408048v1
0601149v1
0608211v2
0212040v1
9904035v1
0301073v1
0507119v1
0503215v1
0302129v1
0201016v1