Abstract
We have investigated antiferromagnetic coupling between semiconductor quantum dots. Electron spin is observed to flip at 80 ps after photoexcitation via the interdot-exchange interaction. The spin relaxation time under the antiferromagnetic order is extended to 10-12 ns, one order of magnitude longer than that in isolated quantum dots. The antiferromagnetic order exists at temperatures lower than 50-80 K. The photoluminescence experiments for various carrier densities show that antiferromagnetic coupling disappears when the electron pairing probability is low. A model calculation based on the Heitler-London approximation supports the finding that the antiferromagnetic order is observable at low temperature.
Original language | English |
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Pages (from-to) | 4278-4281 |
Number of pages | 4 |
Journal | Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers |
Volume | 42 |
Issue number | 7 A |
Publication status | Published - 2003 Jul 1 |
Keywords
- Antiferromagnetism
- Quantum dot
- Semiconductor
- Spin
ASJC Scopus subject areas
- Engineering(all)
- Physics and Astronomy(all)