The study of coherent states (CS) for a quantum mechanical system has
received a lot of attention. The definition, applications, generalizations of
such states have been the subject of work by researchers. A common starting
point of all these approaches is the observation of properties of the original
CS for the harmonic oscillator. It is well-known that they are described
equivalently as (a) eigenstates of the usual annihilation operator, (b) from
a displacement operator acting on a fundamental state and (c) as minimum
uncertainty states. What we observe in the different generalizations proposed
is that the preceding definitions are no longer equivalent and only some of
the properties of the harmonic oscillator CS are preserved.
In this thesis we propose to study a new class of coherent states and
its properties. We note that in one example our CS coincide with the ones
proposed by Glauber where a set of three requirements for such states has
been imposed. The set of our generalized coherent states remains invariant
under the corresponding time evolution and this property is called temporal
stability. Secondly, there is no state which is orthogonal to all coherent states (the coherent states form a total set). The third property is that we
get all coherent states by acting on one of these states [¿fiducial vector¿] with
operators. They are highly non-classical states, in the sense that in general,
their Bargmann functions have zeros which are related to negative regions of
their Wigner functions. Examples of these coherent states with Bargmann
function that involve the Gamma and also the Riemann ¿ functions are represented.
The zeros of these Bargmann functions and the paths of the zeros
during time evolution are also studied. / Libyan Cultural Affairs
| Identifer | oai:union.ndltd.org:BRADFORD/oai:bradscholars.brad.ac.uk:10454/5724 |
| Date | January 2011 |
| Creators | Mohamed, Abdlgader |
| Contributors | Vourdas, Apostolos |
| Publisher | University of Bradford, Department of Computing |
| Source Sets | Bradford Scholars |
| Language | English |
| Detected Language | English |
| Type | Thesis, doctoral, PhD |
| Rights | <a rel="license" href="http://creativecommons.org/licenses/by-nc-nd/3.0/"><img alt="Creative Commons License" style="border-width:0" src="http://i.creativecommons.org/l/by-nc-nd/3.0/88x31.png" /></a><br />The University of Bradford theses are licenced under a <a rel="license" href="http://creativecommons.org/licenses/by-nc-nd/3.0/">Creative Commons Licence</a>. |
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