Quantum control of donor spins in silicon and their environment
<p>Donors in silicon, which combine an electron and nuclear spin, are some of the most promising candidates for quantum information. The electron spin has been proposed as a register with fast manipulation and the nuclear spin as a memory with long coherence times. However, this division reduc...
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| Format: | Thesis |
| Language: | English |
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2015
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| _version_ | 1817932979431800832 |
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| author | Wolfowicz, G |
| author2 | Morton, J |
| author_facet | Morton, J Wolfowicz, G |
| author_sort | Wolfowicz, G |
| collection | OXFORD |
| description | <p>Donors in silicon, which combine an electron and nuclear spin, are some of the most promising candidates for quantum information. The electron spin has been proposed as a register with fast manipulation and the nuclear spin as a memory with long coherence times. However, this division reduces the complexity of the donor system, in particular behaviors emerging from their interaction. In natural silicon, there is also the presence of <sup>29</sup>Si nuclear spins in the donor environment; though they are generally seen as a source of decoherence, they are quantum systems that can be investigated too. The main subject of this thesis is the study of the interactions between these various spins, using different methods to probe and control them.</p> <p>I first concentrate on the coupling between the donor and the <sup>29</sup>Si spins. This coupling can be perturbed by the application of dynamical decoupling on the donor electron spin, whose evolution can be made sensitive to the number of <sup>29</sup>Si spins interacting together. I then propose an error correction scheme using the donor and <sup>29</sup>Si spins, showing key requirements such as coherence times and methods for manipulation and initialization. Secondly, I focus on the donor itself, in a regime where the hyperfine and Zeeman couplings compete with each other. Here, the spin transitions can have different sensitivities to the magnetic environment, and can even be suppressed to first order, resulting in coherence times up to seconds with electron spin-like manipulation times. Controlling this sensitivity was also used to probe the effect of the donor on the <sup>29</sup>Si spin bath evolution. Finally, I use electric fields to modulate the hyperfine coupling within the donor. I first characterize the spins’ sensitivity to the electric field, and then demonstrate electrical switching of the nuclear spin response to an external magnetic excitation.</p> |
| first_indexed | 2024-03-06T21:35:23Z |
| format | Thesis |
| id | oxford-uuid:4613d0f4-e58e-448f-b1cc-1ab273292588 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-12-09T03:46:31Z |
| publishDate | 2015 |
| record_format | dspace |
| spelling | oxford-uuid:4613d0f4-e58e-448f-b1cc-1ab2732925882024-12-08T08:59:08ZQuantum control of donor spins in silicon and their environmentThesishttp://purl.org/coar/resource_type/c_db06uuid:4613d0f4-e58e-448f-b1cc-1ab273292588SiliconCondensed Matter PhysicsQuantum information processingEnglishOxford University Research Archive - Valet2015Wolfowicz, GMorton, JBenjamin, S<p>Donors in silicon, which combine an electron and nuclear spin, are some of the most promising candidates for quantum information. The electron spin has been proposed as a register with fast manipulation and the nuclear spin as a memory with long coherence times. However, this division reduces the complexity of the donor system, in particular behaviors emerging from their interaction. In natural silicon, there is also the presence of <sup>29</sup>Si nuclear spins in the donor environment; though they are generally seen as a source of decoherence, they are quantum systems that can be investigated too. The main subject of this thesis is the study of the interactions between these various spins, using different methods to probe and control them.</p> <p>I first concentrate on the coupling between the donor and the <sup>29</sup>Si spins. This coupling can be perturbed by the application of dynamical decoupling on the donor electron spin, whose evolution can be made sensitive to the number of <sup>29</sup>Si spins interacting together. I then propose an error correction scheme using the donor and <sup>29</sup>Si spins, showing key requirements such as coherence times and methods for manipulation and initialization. Secondly, I focus on the donor itself, in a regime where the hyperfine and Zeeman couplings compete with each other. Here, the spin transitions can have different sensitivities to the magnetic environment, and can even be suppressed to first order, resulting in coherence times up to seconds with electron spin-like manipulation times. Controlling this sensitivity was also used to probe the effect of the donor on the <sup>29</sup>Si spin bath evolution. Finally, I use electric fields to modulate the hyperfine coupling within the donor. I first characterize the spins’ sensitivity to the electric field, and then demonstrate electrical switching of the nuclear spin response to an external magnetic excitation.</p> |
| spellingShingle | Silicon Condensed Matter Physics Quantum information processing Wolfowicz, G Quantum control of donor spins in silicon and their environment |
| title | Quantum control of donor spins in silicon and their environment |
| title_full | Quantum control of donor spins in silicon and their environment |
| title_fullStr | Quantum control of donor spins in silicon and their environment |
| title_full_unstemmed | Quantum control of donor spins in silicon and their environment |
| title_short | Quantum control of donor spins in silicon and their environment |
| title_sort | quantum control of donor spins in silicon and their environment |
| topic | Silicon Condensed Matter Physics Quantum information processing |
| work_keys_str_mv | AT wolfowiczg quantumcontrolofdonorspinsinsiliconandtheirenvironment AT quantumcontrolofdonorspinsinsiliconandtheirenvironment |