Superballistic wavepacket spreading in double kicked rotors

We investigate possible ways in which a quantum wavepacket spreads. We show that in a general class of double kicked rotor systems, a wavepacket may undergo superballistic spreading; i.e., its variance increases as the cubic of time. The conditions for the observed superballistic spreading and two related characteristic time scales are studied. Our results suggest that the symmetry of the studied model and whether it is a Kolmogorov-Arnold-Moser system are crucial to its wavepacket spreading behavior. Our study also sheds new light on the exponential wavepacket spreading phenomenon previously observed in the double kicked rotor systems.Comment: 10 pages, 5 figure

Wave thermalization and its implications for nonequilibrium statistical mechanics

Understanding the rich spatial and temporal structures in nonequilibrium thermal environments is a major subject of statistical mechanics. Because universal laws, based on an ensemble of systems, are mute on an individual system, exploring nonequilibrium statistical mechanics and the ensuing universality in individual systems has long been of fundamental interest. Here, by adopting the wave description of microscopic motion, and combining the recently developed eigenchannel theory and the mathematical tool of the concentration of measure, we show that in a single complex medium, a universal spatial structure - the diffusive steady state - emerges from an overwhelming number of scattering eigenstates of the wave equation. Our findings suggest a new principle, dubbed "the wave thermalization", namely, a propagating wave undergoing complex scattering processes can simulate nonequilibrium thermal environments, and exhibit macroscopic nonequilibrium phenomena.Comment: 10 pages, 7 figure

Symmetry and dynamics universality of supermetal in quantum chaos

Chaotic systems exhibit rich quantum dynamical behaviors ranging from dynamical localization to normal diffusion to ballistic motion. Dynamical localization and normal diffusion simulate electron motion in an impure crystal with a vanishing and finite conductivity, i.e., an "Anderson insulator" and a "metal", respectively. Ballistic motion simulates a perfect crystal with diverging conductivity, i.e., a "supermetal". We analytically find and numerically confirm that, for a large class of chaotic systems, the metal-supermetal dynamics crossover occurs and is universal, determined only by the system's symmetry. Furthermore, we show that the universality of this dynamics crossover is identical to that of eigenfunction and spectral fluctuations described by the random matrix theory.Comment: 10 pages, 8 figure

Concentration-of-measure theory for structures and fluctuations of waves

The emergence of nonequilibrium phenomena in individual complex wave systems has long been of fundamental interests. Its analytic studies remain notoriously difficult. Using the mathematical tool of the concentration of measure (CM), we develop a theory for structures and fluctuations of waves in individual disordered media. We find that, for both diffusive and localized waves, fluctuations associated with the change in incoming waves ("wave-to-wave" fluctuations) exhibit a new kind of universalities, which does not exist in conventional mesoscopic fluctuations associated with the change in disorder realizations ("sample-to-sample" fluctuations), and originate from the coherence between the natural channels of waves -- the transmission eigenchannels. Using the results obtained for wave-to-wave fluctuations, we find the criterion for almost all stationary scattering states to exhibit the same spatial structure such as the diffusive steady state. We further show that the expectations of observables at stationary scattering states are independent of incoming waves and given by their averages with respect to eigenchannels. This suggests the possibility of extending the studies of thermalization of closed systems to open systems, which provides new perspectives for the emergence of nonequilibrium statistical phenomena.Comment: 7 pages, 4 figures, Supplemental Materials(13 pages, 6 figures

Lie-point symmetries of the Lagrangian system on time scales

This letter investigates the Lie point symmetries and conserved quantities of the Lagrangian systems on time scales, which unify the Lie symmetries of the two cases for the continuous and the discrete Lagrangian systems. By defining the infinitesimal transformations' generators and using the invariance of differential equations under infinitesimal transformations, the determining equations of the Lie symmetries on time scales are established. Then the structure equations and the form of conserved quantities with delta derivatives are obtained. The letter also gives brief discussion on the Lie symmetries for the discrete systems. Finally, several examples are designed to illustrate these results.Comment: 14 pages,0 figure

Domain resource integration system

Domain Resource Integrated System (DRIS) is introduced in this paper. DRIS is a hierarchical distributed Internet information retrieval system. This system will solve some bottleneck problems such as long update interval, poor coverage in current web search system. DRIS will build the information retrieval infrastructure of Internet, but not a commercial search engine. The protocol series of DRIS are also detailed in this paper.Comment: 6 pages,4 figure

Identifying two-photon high-dimensional entanglement in transverse patterns

We propose a scheme to explore two-photon high-dimensional entanglement associated with a transverse pattern by means of two-photon interference in a beamsplitter. We find that the topological symmetry of the angular spectrum of the two-photon state governs the nature of the two-photon interference. We prove that the anti-coalescence interference is the signature of two-photon entanglement. On the basis of this feature, we propose a special Mach-Zehnder interferometer incorporated with two spiral phase plates which can change the interference from a coalescence to an anti-coalescence type only for a two-photon entangled state. The scheme is simple and straightforward compared with the test for a Bell inequality.Comment: 3 pages, 3 figure

Phase Randomization and Doppler Peaks in the CMB Angular Power Spectrum

Using the Boltzmann equation with a Langevin-like term describing the stochastic force in a baryon-photon plasma, we investigate the influence of the incoherent electron-photon scattering on the subhorizon evolution of the cosmic microwave radiation. The stochastic fluctuation caused by each collision on average is found to be small. Nevertheless, it leads to a significant Brownian drifting of the phase in the acoustic oscillation, and the coherent oscillations cannot be maintained during their dynamical evolution. As a consequence, the proposed Doppler peaks probably do not exist.Comment: 11 Pages in RevTe

Scale Invariance of Rich Cluster Abundance: A Possible Test for Models of Structure Formation

We investigate the dependence of cluster abundance $n(>M,r_{cl})$, i.e., the number density of clusters with mass larger than $M$ within radius $r_{cl}$, on scale parameter $r_{cl}$. Using numerical simulations of clusters in the CDM cosmogonic theories, we notice that the abundance of rich clusters shows a simple scale invariance such that $n[>(r_{cl}/r_0)^{\alpha}M, r_{cl}]= n(>M,r_0)$, in which the scaling index $\alpha$ remains constant in a scale range where halo clustering is fully developed. The abundances of scale $r_{cl}$ clusters identified from IRAS are found basically to follow this scaling, and yield $\alpha \sim 0.5$ in the range $1.5 < r_{cl} < 4 h^{-1}$Mpc. The scaling gains further supports from independent measurements of the index $\alpha$ using samples of X-ray and gravitational lensing mass estimates. We find that all the results agree within error limit as: $\alpha \sim 0.5 - 0.7$ in the range of $1.5 < r_{cl} < 4 h^{-1}$Mpc. These numbers are in good consistency with the predictions of OCDM ($\Omega_M=0.3$) and LCDM ($\Omega_M+\Omega_{\Lambda} =1$), while the standard CDM model has different behavior. The current result seems to favor models with a low mass density.Comment: 20 pages, 7 figures, accepted for publication in Ap

The CL and PL characteristic of different scale CsI:Na crystals

We investigate the luminescence characteristic of different scale CsI:Na crystals excited via photoluminescence(PL) and cathodoluminescence (CL). The CsI:Na crystals are processed to three samples with different diameter, decreasing from micro-scale to nano-scale. It is found that the nano-scale CsI:Na crystal emits 420nm luminescence by PL, while its emission band is at 315nm and 605nm by CL. The reason for this phenomenon relates to the energy and density of incident particles, and the diameter of CsI:Na crystal. When crystal diameter decreases to nano-scale, the number of surface defects relatively increases, leading to the Na-relative luminescence decreasing. In addition, we have also investigated the CsI:Tl crystal with the same experiment condition. The result indicates that the emission almost has nothing to do with the crystal diameter.Comment: 6 pages,5 figures,1 tabl