10,521 research outputs found

    Experimental study of quantum random number generator based on two independent lasers

    Get PDF
    Quantum random number generator (QRNG) can produce true randomness by utilizing the inherent probabilistic nature of quantum mechanics. Recently, the spontaneous-emission quantum phase noise of the laser has been widely deployed for QRNG, due to its high rate, low cost and the feasibility of chip-scale integration. Here, we perform a comprehensive experimental study of phase-noise based QRNG with two independent lasers, each of which operates in either continuous-wave (CW) or pulsed mode. We implement QRNGs by operating the two lasers in three configurations, namely CW+CW, CW+pulsed and pulsed+pulsed, and demonstrate their tradeoffs, strengths and weaknesses.Comment: 7pages,6figures.It has been accepted by PR

    Characterization and properties of weakly optimal entanglement witnesses

    Get PDF
    We present an analysis of the properties and characteristics of weakly optimal entanglement witnesses, that is witnesses whose expectation value vanishes on at least one product vector. Any weakly optimal entanglement witness can be written as the form of Wwopt=Οƒβˆ’cΟƒmaxIW^{wopt}=\sigma-c_{\sigma}^{max} I, where cΟƒmaxc_{\sigma}^{max} is a non-negative number and II is the identity matrix. We show the relation between the weakly optimal witness WwoptW^{wopt} and the eigenvalues of the separable states Οƒ\sigma. Further we give an application of weakly optimal witnesses for constructing entanglement witnesses in a larger Hilbert space by extending the result of [P. Badzi\c{a}g {\it et al}, Phys. Rev. A {\bf 88}, 010301(R) (2013)], and we examine their geometric properties.Comment: 13 pages, 2 figures, has been extensively redrafted and restructure

    Cycle frequency in standard Rock-Paper-Scissors games: Evidence from experimental economics

    Get PDF
    The Rock-Paper-Scissors (RPS) game is a widely used model system in game theory. Evolutionary game theory predicts the existence of persistent cycles in the evolutionary trajectories of the RPS game, but experimental evidence has remained to be rather weak. In this work we performed laboratory experiments on the RPS game and analyzed the social-state evolutionary trajectories of twelve populations of N=6 players. We found strong evidence supporting the existence of persistent cycles. The mean cycling frequency was measured to be 0.029Β±0.0090.029 \pm 0.009 period per experimental round. Our experimental observations can be quantitatively explained by a simple non-equilibrium model, namely the discrete-time logit dynamical process with a noise parameter. Our work therefore favors the evolutionary game theory over the classical game theory for describing the dynamical behavior of the RPS game.Comment: 7 Page, 3 figure; Keyword: Rock-Paper-Scissors game; cycle; social state; population dynamics; evolutionary trajector
    • …
    corecore