Orbital and spin relaxation in single and coupled quantum dots

Abstract

Phonon-induced orbital and spin relaxation rates of single electron states in lateral single and double quantum dots are obtained numerically for realistic materials parameters. The rates are calculated as a function of magnetic field and interdot coupling, at various field and quantum dot orientations. It is found that orbital relaxation is due to deformation potential phonons at low magnetic fields, while piezoelectric phonons dominate the relaxation at high fields. Spin relaxation, which is dominated by piezoelectric phonons, in single quantum dots is highly anisotropic due to the interplay of the Bychkov-Rashba and Dresselhaus spin-orbit couplings. Orbital relaxation in double dots varies strongly with the interdot coupling due to the cyclotron effects on the tunneling energy. Spin relaxation in double dots has an additional anisotropy due to anisotropic spin hot spots which otherwise cause giant enhancement of the rate at useful magnetic fields and interdot couplings. Conditions for the absence of the spin hot spots in in-plane magnetic fields (easy passages) and perpendicular magnetic fields (weak passages) are formulated analytically for different growth directions of the underlying heterostructure. It is shown that easy passages disappear (spin hot spots reappear) if the double dot system loses symmetry by an xy-like perturbation.

13 pages, 9 figures

References in corpus (9)

• Single-shot read-out of an individual electron spin in a quantum dot
• Zeeman energy and spin relaxation in a one-electron quantum dot
• Single-shot readout of electron spin states in a quantum dot using spin-dependent tunnel rates
• Singlet-triplet decoherence due to nuclear spins in a double quantum dot
• Spin relaxation and anticrossing in quantum dots: Rashba versus Dresselhaus spin-orbit coupling
• Decoherence Rate of Semiconductor Charge Qubit Coupled to Acoustic Phonon Reservoir
• Spin properties of single electron states in coupled quantum dots
• Anisotropy of spin splitting and spin relaxation in lateral quantum dots
• Entanglement distillation by adiabatic passage in coupled quantum dots

Cited by in corpus (12)

• Experimental signature of phonon-mediated spin relaxation
• Geometric phases in semiconductor spin qubits: Manipulations and decoherence
• Triplet-Singlet Spin Relaxation in Quantum Dots with Spin-Orbit Coupling
• Elastic Spin Relaxation Processes in Semiconductor Quantum Dots
• Effect of electron-electron interaction on the phonon-mediated spin relaxation in 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
• Dynamics of coupled spins in quantum dots with strong spin-orbit interaction
• Nonlinear Spin-Charge Dynamics in a Driven Double Quantum Dot
• Spin dephasing due to a random Berry phase
• Control of spin coherence in semiconductor double quantum dots