It and Bit: Decoherence and Information Storage
- Degree Grantor:
- University of California, Santa Barbara. Physics
- Degree Supervisor:
- Wim van Dam
- Place of Publication:
- [Santa Barbara, Calif.]
- Publisher:
- University of California, Santa Barbara
- Creation Date:
- 2013
- Issued Date:
- 2013
- Topics:
- Computer Science and Physics, Quantum
- Keywords:
- Best memory,
Quantum search,
Ultimate information storage,
Grover search,
Decoherent histories, and
Consistent histories - Genres:
- Online resources and Dissertations, Academic
- Dissertation:
- Ph.D.--University of California, Santa Barbara, 2013
- Description:
The second topic is decoherent histories applied to the Grover search problem. The theory of decoherent histories is an attempt to derive classical physics from positing only quantum laws at the fundamental level without notions of a classical apparatus or collapse of the wave-function. Searching for a marked target in a list of N items requires O( N) oracle queries when using a classical computer, while a quantum computer can accomplish the same task in O( N ) queries using Grover's quantum algorithm. We study a closed quantum system executing Grover algorithm in the framework of decoherent histories and find it to be an exactly solvable model, thus yielding an alternate derivation of Grover's famous result. We also subject the Grover-executing computer to a generic external influence without needing to know the specifics of the Hamiltonian insofar as the histories decohere. Depending on the amount of decoherence, which is captured in our model by a single parameter related to the amount of information obtained by the environment, the search time can range from quantum to classical. Thus, we identify a key effect induced by the environment that can adversely affect a quantum computer's performance and demonstrate exactly how classical computing can emerge from quantum laws.
- Physical Description:
- 1 online resource (84 pages)
- Format:
- Text
- Collection(s):
- UCSB electronic theses and dissertations
- Other Versions:
- http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqm&rft_dat=xri:pqdiss:3612010
- ARK:
- ark:/48907/f38c9tcb
- ISBN:
- 9781303731488
- Catalog System Number:
- 990041153130203776
- Copyright:
- Hieu Nguyen, 2013
- Rights:
- In Copyright
- Copyright Holder:
- Hieu Nguyen
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