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On rotated CMV operators and orthogonal polynomials on the unit circle. (English) Zbl 07917828

Summary: Split-step quantum walk operators can be expressed as a generalized version of CMV operators with complex transmission coefficients, which we call rotated CMV operators. Following the idea of Cantero, Moral and Velazquez’s original construction of the original CMV operators from the theory of orthogonal polynomials on the unit circle (OPUC) [M. J. Cantero et al., Linear Algebra Appl. 362, 29–56 (2003; Zbl 1022.42013)], we show that rotated CMV operators can be constructed similarly via a rotated version of OPUCs with respect to the same measure, and admit an analogous \(\mathcal{LM}\)-factorization as the original CMV operators. We also develop the rotated second kind polynomials corresponding to the rotated OPUCs. We then use the \(\mathcal{LM}\)-factorization of rotated alternate CMV operators to compute the Gesztesy-Zinchenko transfer matrices for rotated CMV operators.

MSC:

42C05 Orthogonal functions and polynomials, general theory of nontrigonometric harmonic analysis
33C45 Orthogonal polynomials and functions of hypergeometric type (Jacobi, Laguerre, Hermite, Askey scheme, etc.)
47B36 Jacobi (tridiagonal) operators (matrices) and generalizations
81P45 Quantum information, communication, networks (quantum-theoretic aspects)

Citations:

Zbl 1022.42013

References:

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