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| Author(s): |
Thiago Pedro Mayer Alegre
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Instituto de Física Gleb Wataghin |
| Defense date: | 2008-07-25 |
| Examining board members: |
Gilberto Medeiros Ribeiro;
Leonardo de Souza Menezes;
Sebastião Jose Antonio;
José Antonio Roversi;
Leandro Russovski Tessler
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| Advisor: | Gilberto Medeiros Ribeiro; José Antonio Brum |
| Abstract | |
This thesis proposes and implements a system for quantum information processing, focusing primarily on the associated instrumentation. The basic physical aspects for computation, such as the associated energy and Shannon's entropy, were revisited. InAs:GaAs quantum dots were elected as the physical system of choice for this implementation; in particular, the spin degree of freedom of the trapped electrons was utilized. Therefore, the electronic properties of the quantum dots, as well the g-tensor and the polarization degree, were investigated as a function of the temperature and magnetic field. It was possible to describe the electronic properties within the effective mass formalism, assuming a parabolic lateral confinement. Since the spin degree of freedom was elected as the basis for the quantum computation, a system for spin paramagnetic resonance was devised. The choice for not using a commercial system was made. Instead, a connectorized setup was designed, permitting the semiconductor material to be within a chip, and additionally allowing for focusing the microwave magnetic field above the device. Basically, this chip consisted of a half-wavelength microstrip cavity. A second microstrip cavity with two input ports was also designed to allow the arbitrary control of microwave polarization delivered to the sample. Finally, the quantum state read-out was demonstrated through an optical technique on Nitrogen-Vacancy complexes in diamond. The high sensitivity of the system allows for single spin detection. The selectivity for the optical and spin transitions was characterized and manipulated, using the resonant cavity experimental setup. As a perspective, experiments exploring integration issues on the system are shown (AU) | |
| FAPESP's process: | 04/01228-6 - Unitary operations on a qubit |
| Grantee: | Thiago Pedro Mayer Alegre |
| Support Opportunities: | Scholarships in Brazil - Doctorate (Direct) |