TY - GEN

T1 - Asymptotics of electron flow spin-polarization in quantum waveguides of variable cross-section in presence of magnetic field

AU - Baskin, Lev

AU - Neittaanmäki, Pekka

AU - Sarafanov, Oleg

PY - 2012/12/1

Y1 - 2012/12/1

N2 - We consider electron motion in quantum waveguides with variable cross-sections. The narrows of the waveguide play the role of effective potential barriers for the longitudinal motion of electrons. Two narrows form a quantum resonator where a resonant tunneling can occur. It means that electrons with energy in a small range pass through the resonator with probability near to 1. In presence of magnetic field, the aforementioned range splits into two intervals. Electrons with spin +1/2 can pass through the resonator only if their energies are in one of these intervals and electrons with spin -1/2 can pass only having energies in the second one. Hence, all electrons in the outgoing flow have similarly oriented spins, i. e. The electron flow becomes polarized. The intervals are rapidly decreasing as the diameter of narrows tends to 0, which presents difficulties for numerical simulation of the phenomenon. The full qualitative description of the phenomenon can be given only by asymptotic analysis. We consider an infinite waveguide with two cylindrical ends and two narrows of small diameter. Part of the resonator is placed into magnetic field. We give an asymptotic description of the electron wave propagation in such a waveguide as diameters of the narrows tend to zero.

AB - We consider electron motion in quantum waveguides with variable cross-sections. The narrows of the waveguide play the role of effective potential barriers for the longitudinal motion of electrons. Two narrows form a quantum resonator where a resonant tunneling can occur. It means that electrons with energy in a small range pass through the resonator with probability near to 1. In presence of magnetic field, the aforementioned range splits into two intervals. Electrons with spin +1/2 can pass through the resonator only if their energies are in one of these intervals and electrons with spin -1/2 can pass only having energies in the second one. Hence, all electrons in the outgoing flow have similarly oriented spins, i. e. The electron flow becomes polarized. The intervals are rapidly decreasing as the diameter of narrows tends to 0, which presents difficulties for numerical simulation of the phenomenon. The full qualitative description of the phenomenon can be given only by asymptotic analysis. We consider an infinite waveguide with two cylindrical ends and two narrows of small diameter. Part of the resonator is placed into magnetic field. We give an asymptotic description of the electron wave propagation in such a waveguide as diameters of the narrows tend to zero.

KW - Narrows of waveguide

KW - Resonant energy

KW - Resonant tunneling

KW - Spin-polarization

KW - Transition coefficient

KW - Width of resonant peak

UR - http://www.scopus.com/inward/record.url?scp=84871640165&partnerID=8YFLogxK

M3 - Conference contribution

AN - SCOPUS:84871640165

SN - 9783950353709

T3 - ECCOMAS 2012 - European Congress on Computational Methods in Applied Sciences and Engineering, e-Book Full Papers

SP - 253

EP - 262

BT - ECCOMAS 2012 - European Congress on Computational Methods in Applied Sciences and Engineering, e-Book Full Papers

T2 - 6th European Congress on Computational Methods in Applied Sciences and Engineering, ECCOMAS 2012

Y2 - 10 September 2012 through 14 September 2012

ER -