Spin relaxation and antiferromagnetic coupling in semiconductor quantum dots

We report carrier spin dynamics in highly uniform self-assembled InAs quantum dots and the observation of antiferromagnetic coupling between semiconductor quantum dots. The spin relaxation times in the ground state and the first excited state were measured to be 1.0 and 0.6 ns, respectively, without...

Full description

Saved in:
Bibliographic Details
Published in:Physica. E, Low-dimensional systems & nanostructures Low-dimensional systems & nanostructures, 2006-05, Vol.32 (1), p.354-358
Main Authors: Tackeuchi, A., Kuroda, T., Yamaguchi, K., Nakata, Y., Yokoyama, N., Takagahara, T.
Format: Article
Language:English
Subjects:
Antiferromagnetism
Classical and quantum physics: mechanics and fields
Condensed matter: electronic structure, electrical, magnetic, and optical properties
D’yakonov–Perel
Electron states and collective excitations in thin films, multilayers, quantum wells, mesoscopic and nanoscale systems
Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures
Elliott–Yafet
Exact sciences and technology
InAs
Physics
Quantum computation
Quantum dot
Quantum dots
Quantum information
Semiconductor
Spin
Spin relaxation
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We report carrier spin dynamics in highly uniform self-assembled InAs quantum dots and the observation of antiferromagnetic coupling between semiconductor quantum dots. The spin relaxation times in the ground state and the first excited state were measured to be 1.0 and 0.6 ns, respectively, without the disturbance of inhomogeneous broadening. The measured spin relaxation time decreases rapidly from 1.1 ns at 10 K to 200 ps at 130 K. This large change in the spin relaxation time is well-explained in terms of the mechanism of acoustic phonon emission. In coupled quantum dots, the formation of antiferromagnetic coupling is directly observed. Electron spins are found to flip at 80 ps after photoexcitation via the interdot exchange interaction. The antiferromagnetic coupling exists at temperatures lower than 50–80 K. A model calculation based on the Heitler–London approximation supports the finding that the antiferromagnetic coupling is observable at low temperature. These carrier spin features in quantum dots are suitable for the future quantum computation.
ISSN:1386-9477
1873-1759
DOI:10.1016/j.physe.2005.12.126