Addition energies and density dipole response of quantum rings under the influence of in-plane electric fields

Abstract

Within density functional theory, we address the effect of an in-plane electric field E on the ground state and the density dipole response of a many-electron quantum ring, which is also submitted to a perpendicular magnetic field B. Addition energies and density dipole spectra are discussed as a function of E. For the two-electron case, an exact numerical calculation is performed, obtaining the spin-phase diagram in the E-B plane and showing that transitions between singlet and triplet spin states can be induced by varying the fields. We also find that, in spite of the deformation that E causes in the electronic density, the spin of the ground state of a given electron number ring is very robust, changing little as the strength of the electric field is reasonably increased.

Spin polarization in quantum wires: Influence of Dresselhaus spin-orbit interaction and cross-section effects

“…4 In most cases, ͗k z ͘ = 0 and such approaches consider only effects due to in-plane k-linear terms proportional to the inplane k components ͑k x , k y ͒. 3,8,13,14 For other types of confinements, as well as for materials with a large values of SOI parameters, the k-cubic term must be included in the total Hamiltonian. Recently, the effect of the k-cubic term has appeared to be relevant even for GaAs-AlGaAs, a system with very small SOI parameters.…”

Spin–orbit interaction effects on the optical properties of quantum wires under the influence of in-plane magnetic fields

“…Eq. (16) states that when l s decreases the strength of Rashba SO interaction increases which leads to enhance the energy difference between the energy levels. Additionally, Rashba SO coupling induces pseudomagnetic field [41] that contributes to the enhancement of the energy gap.…”

“…It is well known that an external in-plane magnetic field leads to intriguing energy spectrum especially in the presence of SO interaction [5,16]. When magnetic field is orientated along the wire direction, namely / ¼ 0, energy spectra shows parabola-like shaped subbands.…”

“…Nevertheless, spin physics in semiconductor uses the spin degree of freedom of electrons as a unit of information rather than electron charge and promises potential for future spin-based devices faster, smaller and more powerful than those currently existing [13][14][15][16]. Structural inversion asymmetry in heterostructures induces Rashba SO interaction which can be tuned by changing the gate voltages [17,18].…”

Spin–orbit interaction and magnetic field effects on the energy dispersion of double quantum wire

“…Several theoretical and experimental works investigated the effects of external fields and spin-orbit coupling on the electronic and transport properties in low-dimensional systems [31][32][33][34][35][36][37][38][39][40][41][42]. Mireles and Kirczenow [43] researched the ballistic spin-transport properties of quasi-one-dimensional wires in the presence of the Rashba spin-orbit interaction, Governale and Zülicke [44] presented the effect of Rashba spin-orbit coupling on the band structure, spin accumulation and transport properties of quantum wires.…”