Controlled entanglement dynamics in open quantum systems (Record no. 48838)
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| 000 -LEADER | |
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| fixed length control field | 03226nam a2200241Ia 4500 |
| 008 - FIXED-LENGTH DATA ELEMENTS--GENERAL INFORMATION | |
| fixed length control field | 160627s2012||||xx |||||||||||||| ||und|| |
| 080 ## - UNIVERSAL DECIMAL CLASSIFICATION NUMBER | |
| Universal Decimal Classification number | HBNI Th43 |
| 100 ## - MAIN ENTRY--AUTHOR NAME | |
| Personal name | Sandeep K Goyal |
| Relator term | author |
| 245 ## - TITLE STATEMENT | |
| Title | Controlled entanglement dynamics in open quantum systems |
| 260 ## - PUBLICATION, DISTRIBUTION, ETC. (IMPRINT) | |
| Year of publication | 2012 |
| 300 ## - PHYSICAL DESCRIPTION | |
| Number of Pages | 192p. |
| 502 ## - DISSERTATION NOTE | |
| Dissertation note | 2012 |
| 502 ## - DISSERTATION NOTE | |
| Degree Type | Ph.D |
| 502 ## - DISSERTATION NOTE | |
| Name of granting institution | HBNI |
| 520 3# - SUMMARY, ETC. | |
| Summary, etc | The study of entanglement has gained prominence in recent years due to the advent of fields such as Quantum Optics and Quantum Information Theory — advances that have harnessed such counter-intuitive quantum phenomena into elements of everyday life, improving it in the process. Ideal quantum systems, “closed†to the outside world, remain quantum forever and thus manage to retain entanglement. Real quantum systems, however, are “open†to the environment and are therefore susceptible to the phenomenon of decoherence. The resultant loss of entanglement is a major hindrance to the effectiveness of quantum information tasks. This thesis studies the evolution of entanglement in various types of open quantum systems (OQS) coupled in various ways to local baths. Also studied - existing ways and means of controlling the decay of entanglement and have proposed a new method of doing so. The evolution of entanglement in OQS undergoing Markovian dynamics is studied by using the Lindblad master equation as well as the method of quantum trajectories. The author has analyzed the onset of the phenomenon of entanglement sudden death in finite as well as infinite dimensional OQS, connected either locally to a thermal bath or its squeezed variant, or via a quantum non-demolition-type (QND-type) interaction to a local thermal bath. It is found that the QND-type system-bath interaction works best to conserve entanglement in finite dimensional systems, whereas a squeezed thermal bath causes entanglement sudden death even at zero temperature. Also studied some well-known methods of controlling decoherence in open systems with respect to their ability of preserving entanglement. Some of these procedures include coupling the system to a thermal bath of photonic crystals where the photonic band gap suppresses decoherence, modulation of the system bath frequency in an attempt to contain decoherence, using the method of resonance fluorescence where an external field modulates the transition frequency of the two-qubit systems with each qubit being a two-state atomic system to contain decoherence, and using high-frequency radio waves to decouple the system and bath dynamically and thus reducing decoherence. It is shown through numerical computation, that an ancilla in the ground state extends the lifespan of entanglement in the main system. Increasing the size of the ancilla, that is, increasing the value of n in an n-qubit ancilla slows down entanglement loss for a two-qubit system connected locally to a thermal bath. |
| 650 14 - SUBJECT ADDED ENTRY--TOPICAL TERM | |
| Topical Term | Physics |
| 653 10 - INDEX TERM--UNCONTROLLED | |
| Uncontrolled term | HBNI Th 43 |
| 653 10 - INDEX TERM--UNCONTROLLED | |
| Uncontrolled term | Quantum Entanglement |
| 720 1# - ADDED ENTRY--UNCONTROLLED NAME | |
| Thesis Advisor | Sibasish Ghosh |
| Relator term | Thesis advisor [ths] |
| 856 ## - ELECTRONIC LOCATION AND ACCESS | |
| Uniform Resource Identifier | http://www.imsc.res.in/xmlui/handle/123456789/317 |
| 942 ## - ADDED ENTRY ELEMENTS (KOHA) | |
| Koha item type | THESIS & DISSERTATION |
| Withdrawn status | Lost status | Damaged status | Not for loan | Current library | Full call number | Accession Number | Uniform Resource Identifier | Koha item type |
|---|---|---|---|---|---|---|---|---|
| IMSc Library | HBNI Th43 | 67206 | http://www.imsc.res.in/xmlui/handle/123456789/317 | THESIS & DISSERTATION |