RT Journal Article T1 Theory of 2 δ-kicked quantum rotors A1 Creffield, Charles A1 Fishman, S. A1 Monteiro, T. S. AB We examine the quantum dynamics of cold atoms subjected to pairs of closely spaced kicks from standing waves of light and find behavior quite unlike the well-studied quantum kicked rotor QKR. We show that the quantum phase space has a periodic, cellular structure arising from a unitary matrix with oscillating bandwidth. The corresponding eigenstates are exponentially localized, but scale with a fractional power L~ħ_(-0.75), in contrast to the QKR for which L~ħ_(-1). The effect of intercell (and intracell) transport is investigated by studying the spectral fluctuations with both periodic as well as “open” boundary conditions. PB American Physical Society SN 1539-3755 YR 2006 FD 2006-06 LK https://hdl.handle.net/20.500.14352/51582 UL https://hdl.handle.net/20.500.14352/51582 LA eng NO ©2006 The American Physical Society.We are grateful to Phil Jones for the use of the experimental data in Fig. 1. C.E.C. and T.S.M. acknowledge support from the Engineering and Physical Sciences Research Council. We acknowledge the hospitality of the organizers of the workshop on “Resonances and Periodic Orbits: Spectrum and Zeta Functions in Quantum and Classical Chaos” at Institut Henri Poincaré, Paris, in 2005. S.F. would like to thank Richard Prange and Edward Ott for the hospitality at the University of Maryland, where the work was completed. NO Engineering and Physical Sciences Research Council (EPSRC) (UK) DS Docta Complutense RD 7 abr 2025