title: Parametric number covariance in quantum chaotic spectra.
abstract: We study spectral parametric correlations in quantum chaotic systems and introduce the number covariance as a measure of such correlations. We derive analytic results for the classical random matrix ensembles using the binary correlation method and obtain compact expressions for the covariance. We illustrate the universality of this measure by presenting the spectral analysis of the quantum kicked rotors for the time-reversal invariant and time-reversal noninvariant cases. A local version of the parametric number variance introduced earlier is also investigated.
authors.affiliation: School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110067, India.
authors.lastname: Vinayak
authors.affiliation: School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110067, India.|Department of Physics, H. N. B. Government PG College, Naini, Allahabad 211008, India.
authors.forename: Sandeep
authors.initials: S
authors.lastname: Kumar
authors.affiliation: School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110067, India.
authors.forename: Akhilesh
authors.initials: A
authors.lastname: Pandey