Spin-orbit coupling and anisotropic exchange in two-electron double quantum dots

Abstract

The influence of the spin-orbit interactions on the energy spectrum of two-electron laterally coupled quantum dots is investigated. The effective Hamiltonian for a spin qubit pair proposed in F. Baruffa et al., Phys. Rev. Lett. 104, 126401 (2010) is confronted with exact numerical results in single and double quantum dots in zero and finite magnetic field. The anisotropic exchange Hamiltonian is found quantitatively reliable in double dots in general. There are two findings of particular practical importance: i) The model stays valid even for maximal possible interdot coupling (a single dot), due to the absence of a coupling to the nearest excited level, a fact following from the dot symmetry. ii) In a weak coupling regime, the Heitler-London approximation gives quantitatively correct anisotropic exchange parameters even in a finite magnetic field, although this method is known to fail for the isotropic exchange. The small discrepancy between the analytical model (which employes the linear Dresselhaus and Bychkov-Rashba spin-orbit terms) and the numerical data for GaAs quantum dots is found to be mostly due to the cubic Dresselhaus term.

15 pages, 11 figures

References in corpus (23)

• Single-shot read-out of an individual electron spin in a quantum dot
• Driven coherent oscillations of a single electron spin in a quantum dot
• Coherent control of a single electron spin with electric fields
• Experimental signature of phonon-mediated spin relaxation
• Spin properties of single electron states in coupled quantum dots
• Large anisotropy of spin-orbit interaction in a single InAs self-assembled quantum dot
• Theory of anisotropic exchange in laterally coupled quantum dots
• Geometric phases in semiconductor spin qubits: Manipulations and decoherence
• Triplet-Singlet Spin Relaxation in Quantum Dots with Spin-Orbit Coupling
• Exchange-controlled single-electron-spin rotations in quantum dots
• Failure of standard approximations of the exchange coupling in nanostructures
• Spin-orbit mediated anisotropic spin interaction in interacting electron systems
• Elastic Spin Relaxation Processes in Semiconductor Quantum Dots
• Spin-orbit effect on electron-electron interaction and fine structure of electron complexes in quantum dots
• Spin-orbit interaction in quantum dots in the presence of exchange correlations
• Spin entanglement induced by spin-orbit interactions in coupled quantum dots
• Reexamination of spin decoherence in semiconductor quantum dots from equation-of-motion approach
• Triplet-singlet relaxation in semiconductor single and double quantum dots
• Anisotropic spin relaxation in quantum dots
• Spin Exciton in quantum dot with spin orbit coupling in high magnetic field
• Dynamics of coupled spins in quantum dots with strong spin-orbit interaction
• Pulse-pumped double quantum dot with spin-orbit coupling
• Nonlinear Spin-Charge Dynamics in a Driven Double Quantum Dot

Cited by in corpus (22)

• Semiconductor Spin Qubits
• Singlet-triplet splitting in double quantum dots due to spin orbit and hyperfine interactions
• Robust Single-Shot Spin Measurement with 99.5% Fidelity in a Quantum Dot Array
• Exchange-based CNOT gates for singlet-triplet qubits with spin orbit interaction
• Tuning of the spin-orbit interaction in a quantum dot by an in-plane magnetic field
• Footprints of hyperfine, spin-orbit, and decoherence effects in Pauli spin blockade
• Theory of Spin Relaxation in Two-Electron Lateral Coupled Quantum Dots
• Theory of Spin Relaxation in Two-Electron Lateral Coupled Si/SiGe Quantum Dots
• Negative exchange interactions in coupled few-electron quantum dots
• Spin Manipulation and Relaxation in Spin-Orbit Qubits
• Interplay of exchange and superexchange in triple quantum dots
• Inverted Singlet-Triplet Qubit Coded on a Two-Electron Double Quantum Dot
• Optical measurement and modeling of interactions between two hole or two electron spins in coupled InAs quantum dots
• Spin ordering in magnetic quantum dots: From core-halo to Wigner molecules
• Singlet-triplet avoided crossings and effective $g$ factor versus spatial orientation of spin-orbit-coupled quantum dots
• Spin-Orbit Interaction Enabled High-Fidelity Two-Qubit Gates
• Energy spectra of three electrons in SiGe/Si/SiGe laterally coupled triple quantum dots
• Random spin-orbit gates in the system of a Topological insulator and a Quantum dot
• Theory on electron-phonon spin dehphasing in GaAs multi-electron double quantum dots
• Comparison of methods for computing the exchange energy in laterally coupled quantum dots
• Exploring Entanglement Spectrum and Phase Diagram in multi-electron Quantum Dot Chains
• Negative exchange interaction in Si quantum dot arrays via valley-phase induced ${\mathbb{Z}}_2$ gauge field