coupled quantum dots brittany mcclinton ee c235 nanofabrication 3/17/08
Post on 23-Jan-2016
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Asymmetric quantum dots are coupled through
an applied electric field
E. A. Stinaff et al, Science 311, 636 (2006).
Why CQDs?
Coupling With Applied Field
Fabrication
Coupling Mechanism
Scaling Up
1 Scalable qubits Each dot represents a qubit
2 Long-lived Spin of unpaired electron or hole
3 Ultra-fast Optically excited states as auxiliary levels
(laser pulses)
1 2 3
Asymmetric pair of InAs Quantum Dots
Exciton Notation:
Indirect
Resonance
Direct
Coupling = Resonance = Anticrossing Condition: Optical Excitation,
Tunneling, Indirect Transitions Possible
Bottom Layer InAs QDs
GaAs Tunneling Barrier
Top Layer InAs QDs
Asymmetric QDs by Design
Distinct Optical Transitions
Distinguishing Individual QDs
…Scalability
Model Without
Tunneling & Spin
1 2 3Model WithTunneling &
Spin
Experimental
SpectrumResonance At
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