Spin properties of single electron states in coupled quantum dots

Abstract

Spin properties of single electron states in laterally coupled quantum dots in the presence of a perpendicular magnetic field are studied by exact numerical diagonalization. Dresselhaus (linear and cubic) and Bychkov-Rashba spin-orbit couplings are included in a realistic model of confined dots based on GaAs. Group theoretical classification of quantum states with and without spin orbit coupling is provided. Spin-orbit effects on the g-factor are rather weak. It is shown that the frequency of coherent oscillations (tunneling amplitude) in coupled dots is largely unaffected by spin-orbit effects due to symmetry requirements. The leading contributions to the frequency involves the cubic term of the Dresselhaus coupling. Spin-orbit coupling in the presence of magnetic field leads to a spin-dependent tunneling amplitude, and thus to the possibility of spin to charge conversion, namely spatial separation of spin by coherent oscillations in a uniform magnetic field. It is also shown that spin hot spots exist in coupled GaAs dots already at moderate magnetic fields, and that spin hot spots at zero magnetic field are due to the cubic Dresselhaus term only.

16 pages, 12 figures

References in corpus (6)

• 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
• Spin relaxation and anticrossing in quantum dots: Rashba versus Dresselhaus spin-orbit coupling
• Energy levels of a parabolically confined quantum dot in the presence of spin-orbit interaction
• Electrical readout of a spin qubit without double occupancy

Cited by in corpus (8)

• Orbital and spin relaxation in single and coupled quantum dots
• Elastic Spin Relaxation Processes in Semiconductor Quantum Dots
• Effect of electron-electron interaction on the phonon-mediated spin relaxation in quantum dots
• Spin entanglement induced by spin-orbit interactions in coupled quantum dots
• Pulse-pumped double quantum dot with spin-orbit coupling
• Nonlinear Spin-Charge Dynamics in a Driven Double Quantum Dot
• Characteristic molecular properties of one-electron double quantum rings under magnetic fields
• Coupling of bonding and antibonding electron orbitals in double quantum dots by spin-orbit interaction