scholarly journals A Schwinger Term in q-Deformed su(2) Algebra

1997 ◽  
Vol 12 (06) ◽  
pp. 403-409 ◽  
Author(s):  
Kazuo Fujikawa ◽  
Harunobu Kubo ◽  
C. H. Oh

An extra term generally appears in the q-deformed su(2) algebra for the deformation parameter q= exp 2π iθ, if one combines the Biedenharn–Macfarlane construction of q-deformed su(2), which is a generalization of Schwinger's construction of conventional su(2), with the representation of the q-deformed oscillator algebra which is manifestly free of negative norm. This extra term introduced by the requirement of positive norm is analogous to the Schwinger term in current algebra. Implications of this extra term on the Bloch electron problem analyzed by Wiegmann and Zabrodin are briefly discussed.

1995 ◽  
Vol 10 (33) ◽  
pp. 2543-2551 ◽  
Author(s):  
KAZUO FUJIKAWA ◽  
L.C. KWEK ◽  
C.H. OH

The quantum deformation of the oscillator algebra and its implications on the phase operator are studied from a viewpoint 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 dim ker a–dim ker a†=1 which allows only a nonhermitian phase operator with dim ker eiφ–dim ker(eiφ)†=1. For q=exp(2πiθ) with a rational θ, one formally obtains the singular situation dim ker a=∞ and dim ker a†=∞, which allows a hermitian phase operator with dim ker eiΦ–dim ker(eiΦ)†=0 as well as the nonhermitian one with dim ker eiφ– dim ker(eiφ)†=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).


2012 ◽  
Vol 27 (21) ◽  
pp. 1250114 ◽  
Author(s):  
A. M. GAVRILIK ◽  
I. I. KACHURIK

A three-parametric two-sided deformation of Heisenberg algebra (HA), with p, q-deformed commutator in the L.H.S. of basic defining relation and certain deformation of its R.H.S., is introduced and studied. The third deformation parameter μ appears in an extra term in the R.H.S. as pre-factor of Hamiltonian. For this deformation of HA we find novel properties. Namely, we prove it is possible to realize this (p, q, μ)-deformed HA by means of some deformed oscillator algebra. Also, we find the unusual property that the deforming factor μ in the considered deformed HA inevitably depends explicitly on particle number operator N. Such a novel N-dependence is special for the two-sided deformation of HA treated jointly with its deformed oscillator realizations.


1997 ◽  
Vol 12 (18) ◽  
pp. 1335-1341 ◽  
Author(s):  
Harunobu Kubo

A difference operator realization of quantum deformed oscillator algebra ℋq(1) with a Casimir operator freedom is introduced. We show that this ℋq(1) has a nonlinear mapping to the deformed quantum su(2) which was introduced by Fujikawa et al. We also examine the cyclic representation obtained by this difference operator realization and the possibility to analyze a Bloch electron problem by ℋq(1).


2014 ◽  
Vol 29 (06) ◽  
pp. 1450028 ◽  
Author(s):  
S. Aghaei ◽  
A. Chenaghlou

The Dirac equation with scalar and vector potentials of equal magnitude is considered. For the two-dimensional harmonic oscillator superintegrable potential, the superintegrable potentials of E8 (case (3b)), S4 and S2, the Schrödinger-like equations are studied. The quadratic algebras of these quasi-Hamiltonians are derived. By using the realization of the quadratic algebras in a deformed oscillator algebra, the structure function and the energy eigenvalues are obtained.


2000 ◽  
Vol 100 (2) ◽  
pp. 2061-2076 ◽  
Author(s):  
V. V. Borzov ◽  
E. V. Damaskinskii ◽  
S. B. Yegorov

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