Page 1 |
Save page Remove page | Previous | 1 of 256 | Next |
|
small (250x250 max)
medium (500x500 max)
large ( > 500x500)
Full Resolution
All (PDF)
|
This page
All
Subset |
TOPICS IN QUANTUM INFORMATION AND THE THEORY OF OPEN
QUANTUM SYSTEMS
by
Ognyan Oreshkov
A Dissertation Presented to the
FACULTY OF THE GRADUATE SCHOOL
UNIVERSITY OF SOUTHERN CALIFORNIA
In Partial Fulfillment of the
Requirements for the Degree
DOCTOR OF PHILOSOPHY
(PHYSICS)
May 2008
Copyright 2008 Ognyan Oreshkov
Object Description
| Title | Topics in quantum information and the theory of open quantum systems |
| Author | Oreshkov, Ognyan |
| Author email | oreshkov@usc.edu |
| Degree | Doctor of Philosophy |
| Document type | Dissertation |
| Degree program | Physics |
| School | College of Letters, Arts and Sciences |
| Date defended/completed | 2008-03-28 |
| Date submitted | 2008 |
| Restricted until | Unrestricted |
| Date published | 2008-04-28 |
| Advisor (committee chair) | Brun, Todd A. |
| Advisor (committee member) |
Lidar, Daniel Zanardi, Paolo Haas, Stephan Dappen, Werner |
| Abstract | This thesis examines seven topics in quantum information and the theory of open quantum systems. The first one concerns weak measurements and their universality as a means of generating quantum measurements. It is shown that every generalized measurement can be decomposed into a sequence of weak measurements which allows us to think of measurements as resulting form continuous stochastic processes. The second topic concerns an application of the decomposition into weak measurements to the theory of entanglement. Necessary and sufficient differential conditions for entanglement monotones are derived, and are used tofind a new entanglement monotone for three-qubit states. The third topic examines the performance of different master equations for the description of non-Markovian dynamics. The system studied is a qubit coupled to a spin bath via the Ising interaction. The fourthtopic studies continuous quantum error-correction in the case of non-Markovian decoherence. It is shown that due to the existence of a Zeno regime in non-Markovian dynamics, the performance of continuous quantum error correction may exhibit a quadratic improvement if the time resolution of the error-correcting operations is sufficiently high.; The fifth topic concerns conditions for correctability of subsystem codes in the case of continuous decoherence. The obtained conditions on the Lindbladian and the system-environment Hamiltonian can be thought of as generalizations of the previously known conditions for noiseless sub-systems to the case where the subsystem is time-dependent. The sixth topic examines the robustness of quantum error-correcting codes against initialization errors. It is shown that operator codes are robust against imperfect initialization without the need for restriction of the standard error-correction conditions. For this purpose, a new measure of fidelity for encoded information is introduced and its properties are discussed. The last topic concerns holonomic quantum computation and stabilizer codes. A fault-tolerant scheme for holonomic computations is presented, demonstrating the scalability of the holonomic method. The scheme opens the possibility for combining the benefits of error correction with the inherent resilience of the holonomic approach. |
| Keyword | weak measurements; entanglement; non-Markovian dynamics; continuous quantum error correction; operator quantum error correction; holonomic quantum computation |
| Language | English |
| Part of collection | University of Southern California dissertations and theses |
| Publisher (of the original version) | University of Southern California |
| Place of publication (of the original version) | Los Angeles, California |
| Publisher (of the digital version) | University of Southern California. Libraries |
| Type | texts |
| Legacy record ID | usctheses-m1201 |
| Rights | Oreshkov, Ognyan |
| Repository name | Libraries, University of Southern California |
| Repository address | Los Angeles, California |
| Repository email | http://www.usc.edu/isd/libraries/services/ask_a_librarian/email/ |
| Filename | etd-Oreshkov-20080428 |
| Archival file | uscthesesreloadpub_Volume44/etd-Oreshkov-20080428.pdf |
Description
| Title | Page 1 |
| Full text | TOPICS IN QUANTUM INFORMATION AND THE THEORY OF OPEN QUANTUM SYSTEMS by Ognyan Oreshkov A Dissertation Presented to the FACULTY OF THE GRADUATE SCHOOL UNIVERSITY OF SOUTHERN CALIFORNIA In Partial Fulfillment of the Requirements for the Degree DOCTOR OF PHILOSOPHY (PHYSICS) May 2008 Copyright 2008 Ognyan Oreshkov |
Comments
Post a Comment for Page 1
