Coulomb interactions of few (N) electrons confined in a disk-shaped quantum dot, with a large magnetic field B=B-* applied in the z direction (orthogonal to the dot), produce a fully spin-polarized ground state. We numerically study the splitting of the levels corresponding to the multiplet of total spin S=N/2 (each labeled by a different total angular momentum J(z)) in the presence of an electric field parallel to B, coupled to S by a Rashba term. We find that the first excited state is a spin exciton with a reversed spin at the origin. This is reminiscent of the quantum Hall ferromagnet at filling one, which has the skyrmionlike state as its first excited state. The spin-exciton level can be tuned with the electric field and infrared radiation can provide energy and angular momentum to excite it.

Spin exciton in a quantum dot with spin-orbit coupling at high magnetic field

Lucignano P;Tagliacozzo A
2004

Abstract

Coulomb interactions of few (N) electrons confined in a disk-shaped quantum dot, with a large magnetic field B=B-* applied in the z direction (orthogonal to the dot), produce a fully spin-polarized ground state. We numerically study the splitting of the levels corresponding to the multiplet of total spin S=N/2 (each labeled by a different total angular momentum J(z)) in the presence of an electric field parallel to B, coupled to S by a Rashba term. We find that the first excited state is a spin exciton with a reversed spin at the origin. This is reminiscent of the quantum Hall ferromagnet at filling one, which has the skyrmionlike state as its first excited state. The spin-exciton level can be tuned with the electric field and infrared radiation can provide energy and angular momentum to excite it.
2004
Istituto dei Sistemi Complessi - ISC
Istituto Superconduttori, materiali innovativi e dispositivi - SPIN
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.14243/148351
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