Symmetry induced hole-spin mixing in quantum dot molecules

Abstract

We investigate theoretically the spin purity of single holes confined in vertically coupled GaAs/AlGaAs quantum dots (QDs) under longitudinal magnetic fields. A unique behavior is observed for triangular QDs, by which the spin is largely pure when the hole is in one of the dots, but it becomes strongly mixed when an electric field is used to drive it into molecular resonance. The spin admixture is due to the valence band spin-orbit interaction, which is greatly enhanced in C3h symmetry environments. The strong yet reversible electrical control of hole spin suggests that molecules with C3-symmetry QDs, like those obtained with [111] growth, can outperform the usual C2-symmetry QDs obtained with [001] growth for the development of scalable qubit architectures.

arXiv comment5-pages manuscript + supplementary information. Version to be published in PRB Rapid Communications

References in corpus (20)

• Prospects for Spin-Based Quantum Computing
• Observation of extremely slow hole spin relaxation in self-assembled quantum dots
• Optical control of one and two hole spins in interacting quantum dots
• Electrically tunable g-factors in quantum dot molecular spin states
• Coherent optical control of the spin of a single hole in a quantum dot
• Theory of excitonic spectra and entanglement engineering in dot molecules
• Top-gate defined double quantum dots in InAs nanowires
• Scalable qubit architecture based on holes in quantum dot molecules
• Optical Spin Noise of a Single Hole Spin Localized in an (InGa)As Quantum Dot
• Hole Spin Mixing in InAs Quantum Dot Molecules
• Spin Orbit Mediated Manipulation of Heavy Hole Spin Qubit in Gated Semiconductor Nanodevices
• Dark-bright mixing of interband transitions in symmetric semiconductor quantum dots
• High resolution coherent population trapping on a single hole spin in a semiconductor
• High fidelity optical preparation and coherent Larmor precession of a single hole in an InGaAs quantum dot molecule
• Strong electrically tunable exciton g-factors in an individual quantum dots due to hole orbital angular momentum quenching
• Fast preparation of single hole spin in InAs/GaAs quantum dot in Voigt geometry magnetic field
• Electric-field Manipulation of the Lande' g Tensor of Holes in In0.5Ga0.5As/GaAs Self-assembled Quantum Dots
• Spin-echo dynamics of a heavy hole in a quantum dot
• Fast high fidelity hole spin initialization in a single InGaAs quantum dot
• All-electric qubit control in heavy hole quantum dots via non-Abelian geometric phases

Cited by in corpus (4)

• Control of a spin qubit in a lateral GaAs quantum dot based on symmetry of gating potential
• Theory of electrons, holes and excitons in GaAs polytype quantum dots
• Incorporation of random alloy GaBi${}_x$As${}_{1-x}$ barriers in InAs quantum dot molecules (I): energy levels and confined hole states
• Incorporation of random alloy GaBi${}_x$As${}_{1-x}$ barriers in InAs quantum dot molecules: alloy strain and orbital effects towards enhanced tunneling