Optical measurement and modeling of interactions between two hole or two electron spins in coupled InAs quantum dots

Abstract

Two electron spins in quantum dots coupled through coherent tunneling are generally acknowledged to approximately obey Heisenberg isotropic exchange. This has not been established for two holes. Here we measure the spectra of two holes and of two electrons in two vertically stacked self-assembled InAs quantum dots using optical spectroscopy as a function of electric and magnetic fields. We find that the exchange is approximately isotropic for both systems, but that significant asymmetric contributions, arising from spin-orbit and Zeeman interactions combined with spatial asymmetries, are required to explain large anticrossings and fine-structure energy splittings in the spectra. Asymmetric contributions to the isotropic Hamiltonian for electrons are of the order of a few percent while those for holes are an order of magnitude larger.

5 pages, 3 figures

References in corpus (22)

• Quantum Computation with Quantum Dots
• Electron transport through double quantum dots
• Coupled quantum dots as quantum gates
• Relaxation, dephasing, and quantum control of electron spins in double quantum dots
• Low-temperature spin relaxation in n-type GaAs
• Ultrafast optical control of entanglement between two quantum dot spins
• Coherent control and suppressed nuclear feedback of a single quantum dot hole qubit
• Anisotropic exchange interaction of localized conduction-band electrons in semiconductor structures
• Hole - Nuclear Spin Interaction in Quantum Dots
• Optical control of one and two hole spins in interacting quantum dots
• Spin interactions and switching in vertically tunnel-coupled quantum dots
• Electrically tunable g-factors in quantum dot molecular spin states
• Singlet-triplet splitting in double quantum dots due to spin orbit and hyperfine interactions
• Direct measurement of the hole-nuclear spin interaction in single quantum dots
• Spin Fine Structure in Optically Excited Quantum Dot Molecules
• Hybridization and spin decoherence in heavy-hole quantum dots
• Symmetry of anisotropic exchange interactions in semiconductor nanostructures
• Hole Spin Mixing in InAs Quantum Dot Molecules
• Theory of anisotropic exchange in laterally coupled quantum dots
• Spin-orbit coupling and anisotropic exchange in two-electron double quantum dots
• Detection and measurement of the Dzyaloshinskii-Moriya interaction in double quantum dot systems
• Time dependent configuration interaction simulations of spin swap in spin orbit coupled double quantum dots

Cited by in corpus (5)

• Non-local nuclear spin quieting in quantum dot molecules: Optically-induced extended two-electron spin coherence time
• Anisotropic exchange coupling in a nanowire double quantum dot with strong spin-orbit coupling
• Spin noise spectroscopy of quantum dot molecules
• The magneto-optics in quantum wires comprised of vertically stacked quantum dots: A calling for the magnetoplasmon qubits
• Single-particle and collective excitations in quantum wires comprised of vertically stacked quantum dots: Finite magnetic field