The spectral properties of ‘‘chaotic quantum systems’’ are modeled using tridiagonal random matrices. Unlike the Gaussian-orthogonal-ensemble (GOE) method, both the smooth and fluctuating parts of the spectral properties can be modeled simultaneously. We model the recent experiment by Gräf et al. [Phys. Rev. Lett. 69, 1296 (1992)] as an example. This approach also provides an approximate construction of a GOE-type spectrum without any need for unfolding. By changing one control variable, one can bring the model from obeying δ-function level-spacing statistics, to being GOE-like or to being Poisson-like.

• Received 21 September 1992

DOI:https://doi.org/10.1103/PhysRevE.47.4063