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Optical manipulation of a single Mn spin in a CdTe-based quantum dot
M Goryca1, T Kazimierczuk, M Nawrocki
1Institute of Experimental Physics, University of Warsaw, Hoza 69, 00-681 Warsaw, Poland. mgoryca@fuw.edu.pl
Physical Review Letters
|October 2, 2009
Summary
Researchers demonstrated optical writing of information onto the spin state of manganese (Mn) ions in coupled quantum dots. This quantum dot spin manipulation achieved storage times up to hundreds of microseconds, paving the way for quantum information applications.
Area of Science:
- Quantum dots
- Spintronics
- Materials science
Background:
- Self-assembled semiconductor quantum dots offer a platform for studying quantum phenomena.
- Introducing magnetic ions like manganese (Mn) into quantum dots enables spin-based functionalities.
Purpose of the Study:
- To investigate the optical control and storage of spin information in coupled CdTe quantum dots containing a single Mn ion.
- To characterize the dynamics of Mn spin orientation and storage.
Main Methods:
- Continuous wave and modulated photoluminescence spectroscopy.
- Photoluminescence excitation spectroscopy.
- Photon correlation measurements.
- Optical spin manipulation using spin-polarized carriers.
Main Results:
- Demonstrated optical writing of information on the Mn ion spin state via carrier transfer from a neighboring quantum dot.
- Measured Mn spin orientation times ranging from 20 to 100 nanoseconds, dependent on excitation power.
- Achieved enhanced information storage times of hundreds of microseconds in the dark by applying a static magnetic field (1 T).
- Validated experimental findings using simple rate equation models.
Conclusions:
- Coupled quantum dots with single Mn ions can be used for optical information writing and storage.
- The Mn spin state dynamics are controllable and can be significantly prolonged with external magnetic fields.
- This system shows promise for developing quantum memory and spintronic devices.
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