| EPSRC Reference: |
EP/D025303/1 |
| Title: |
Coherent optical maniulation and spectroscopy of single quantum dots for quantum computing |
| Principal Investigator: |
Langbein, Professor WW |
| Other Investigators: |
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| Researcher Co-Investigators: |
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| Project Partners: |
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| Department: |
School of Physics and Astronomy |
| Organisation: |
Cardiff University |
| Scheme: |
First Grant Scheme Pre-FEC |
| Starts: |
01 October 2005 |
Ends: |
30 September 2007 |
Value (£): |
124,708
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| EPSRC Research Topic Classifications: |
| Materials Characterisation |
Quantum Optics & Information |
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| EPSRC Industrial Sector Classifications: |
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| Related Grants: |
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| Panel History: |
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Summary on Grant Application Form |
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Semiconductor quantum dots are atom-like entities in a solid-state environment, with typical sizesof 10nm. Self-organized growth methods allow to produce them with a high degree of perfectioninside a crystalline semiconductor host material. As their size, shape, and composition can becontrolled at will, they have optical properties that can be tailored to a large extend. This haslead to their application in light-emitting devices and in the optical communications technology.Modern experiments are capable of measuring the optical properties of individual quantum dots,allowing to investigate their discrete quantum-mechanical level structure. This discrete levelstructure makes them a promising candidate for the information carrier, the qubit, in quantumcomputation. Quantum computation relies on the coherence properties of the quantum dots, and thecontrolled coupling between individual dots. The coherence describes the persistence of a phaserelation between the excitation of the different levels. The proposed research measures thecoherence dynamics in individual quantum dots using the non-linear optical spectroscopy techniqueof four-wave mixing. In this technique, three light pulses are mixed by the nonlinearity in thequantum dot, and the mixed product is emitted as a fourth light pulse. The application of transientfour-wave mixing to single quantum dots is an experimental challenge, and was demonstrated for theonly recently by the PI first time. We will use four-wave mixing to determine the coherent couplingbetween different quantum dots. Once this coupling is measured, optical control pulses will be usedto manipulate the coherence in a well defined manner. In order to create the necessary opticalcontrol pulses, an improved optical pulse shaper will be developed and realized. It will allow tocreate optical pulses of arbitrary time evolution in phase and amplitude up to a high complexity.The pulses will be applied to implement quantum computational operations on single quantum dots andcoupled quantum dot pairs by optical control of the coherence. Such a demonstration will be adecisive step towards the implementation of quantum computing algorithms in a solid stateenvironment.
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Key Findings |
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This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
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Potential use in non-academic contexts |
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This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
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Impacts |
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| Description |
This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk |
| Summary |
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| Date Materialised |
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Sectors submitted by the Researcher |
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This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
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| Project URL: |
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| Further Information: |
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| Organisation Website: |
http://www.cf.ac.uk |