Q-Deformed Oscillator Algebra and an Index Theorem for the Photon Phase Operator

The quantum deformation of the oscillator algebra and its implications on the phase operator are studied from a view point of an index theorem by using an explicit matrix representation. For a positive deformation parameter $q$ or $q=exp(2πiθ)$ with an irrational $θ$, one obtains an index condition...

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Bibliographic Details
Main Authors: Fujikawa, Kazuo, Kwek, L. C., Oh, C. H.
Format: Text
Language:unknown
Published: arXiv 1995
Subjects:
DML
Online Access:https://dx.doi.org/10.48550/arxiv.hep-th/9504136
https://arxiv.org/abs/hep-th/9504136
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Summary:The quantum deformation of the oscillator algebra and its implications on the phase operator are studied from a view point of an index theorem by using an explicit matrix representation. For a positive deformation parameter $q$ or $q=exp(2πiθ)$ with an irrational $θ$, one obtains an index condition $\dml a - \dml a^{\dagger} = 1$ which allows only a non-hermitian phase operator with $\dml \expon^{i φ} - \dml (\expon^{iφ})^{\dagger} = 1$. For $q=exp(2πiθ)$ with a rational $θ$ , one formally obtains the singular situation $\dml a =\infty$ and $ \dml a^{\dagger} = \infty$, which allows a hermitian phase operator with $\dml \expon^{i Φ} - \dml (\expon^{iΦ})^{\dagger} = 0$ as well as the non-hermitian one with $\dml \expon^{i φ} - \dml (\expon^{iφ})^{\dagger} = 1$. Implications of this interpretation of the quantum deformation are discussed. We also show how to overcome the problem of negative norm for $q=exp(2πiθ)$. : 13 pages. A rather substantial revision has been made by employing an explicit matrix representation of q-deformed oscillator algebra. In particular, it is shown how to overcome the problem of negative norm for the deformation parameter at a primitive root of unity. The revised version is in press for Mod. Phys. Lett. A