The coherence of quantum dot confined electron- and hole-spin in low external magnetic field

Abstract

We investigate experimentally and theoretically the temporal evolution of the spin of the conduction band electron and that of the valence band heavy hole, both confined in the same semiconductor quantum dot. In particular, the coherence of the spin purity in the limit of a weak externally applied magnetic field, comparable in strength to the Overhauser field due to fluctuations in the surrounding nuclei spins. We use an all-optical pulse technique to measure the spin evolution as a function of time after its initialization. We show for the first time that the spin purity performs complex temporal oscillations which we quantitatively simulate using a central spin model. Our model encompasses the Zeeman and the hyperfine interactions between the spin and the external and Overhauser fields, respectively. Our novel studies are essential for the design and optimization of quantum-dot-based entangled multi-photon sources. Specifically, cluster and graph states, which set stringent limitations on the magnitude of the externally applied field.

9 pages, 4 figures, and 1 table

References in corpus (9)

• Entangled Photon Pairs from Semiconductor Quantum Dots
• Deterministic Generation of a Cluster State of Entangled Photons
• A photonic cluster state machine gun
• Spin decoherence of a heavy hole coupled to nuclear spins in a quantum dot
• Optically generated 2-dimensional photonic cluster state from coupled quantum dots
• Hole - Nuclear Spin Interaction in Quantum Dots
• Excitation spectroscopy of single quantum dots at tunable positive, neutral and negative charge states
• Electron-nuclear dynamics in a quantum dot under non-unitary electron control
• Complete state tomography of a quantum dot confined spin qubit

Cited by in corpus (4)

• Deterministic generation of entangled photonic cluster states from quantum dot molecules
• Probing the dynamics and coherence of a semiconductor hole spin via acoustic phonon-assisted excitation
• Continuous and deterministic all-photonic cluster state of indistinguishable photons
• Eliminating the confined dark-exciton qubit precession using an externally applied magnetic field