Compact random number generator (RNG) is presented and demonstrated on the basis of field effect transistor connected in a such a way that avalanche electron current emerges when an input voltage exceeds the threshold value. The avalanche character of this phenomenon provides true randomness and large noise potential in wide spectral band at extremely small feeding electrical power. Created device is robust and it consists of compact elements with the possibility of digital signal acquisition from standard internal or external analogous to digital transducer. Created RNG has been tested. One hundred sequences each with 300000 bits length were tested using 15 separate tests of National Institute of Standards and Technology (NIST) with application of simple “linear post processing”. The results of testing are the following: all 100 sequences had passed NIST test series.
Configuration of three resonators connected located in triangular scheme is considered for implementation of single and two-qubit gates. Each of the resonators can be coupled with its three-level atom and with neighbor resonator in defined moment of time. The regimes for coherent control of atom-photonic molecule states in the studied scheme and realization of single- and two qubit gates on this basis are theoretically investigated. The two qubit gate is considered in two various regimes: at the sequential switching on the interactions with step by step transfer of excitation and when central resonator is coupled simultaneously with two side resonators and excitation is transferring in the course of single process. Comparison of these two approaches is performed and recommendations for the construction of quantum computers on the atom-photon molecular states are presented.
Natural language processing is efficient using quantum neural networks including multiqubit controlled NOT gates with multiple control qubits and a single target qubit. We propose here a photonic miltiqubit controlled NOT gate based on a multi-wave mixing process in a cavity. Theory of such a multiqubit gate is constructed using input-output formalism. Parameters matching condition is found that must be fulfilled for successful gate operation. Recommendations are given for the construction of quantum neural networks that are able to solve various practical problems of natural language processing.
We present a classical stochastic simulation technique of quantum Branching programs. This technique allows to prove the following relations among complexity classes: PrQP-BP &subuline; PP-BP and BQP-BP &subuline; PP-BP. Here BPP-BP and PP-BP stands for the classes of functions computable with bounded error and unbounded error respectively by stochastic branching program of polynomial size. BQP-BP and PrQP-BP stands the classes of functions computable with bounded error and unbounded error respectively by quantum branching program of polynomial size. Second. We present two different types, of complexity lower bounds for quantum nonuniform automata (OBDDs). We call them "metric" and "entropic" lower bounds in according to proof technique used. We present explicit Boolean functions that show that these lower bounds are tight enough. We show that when considering "almost all Boolean functions" on n variables our entropic lower bounds gives exponential (2c(δ)(n-log n)) lower bound for the width of quantum OBDDs depending on the error δ allowed.
In the talk we present results on comparitve power of classical and quantum computational models. We focus on two well known in Computer Science models: finite automata which is known as uniform computational model and branching programs which is known as nonuniform computational model.
We present a classical probabilistic simulation technique of quantum Turing machines As a corollary of this technique we obtain several results on relationship among classical and quantum complexity classes such as: PrQP PP BQP PP and PrQSPACE(S(n)) PrPSPACE(S(n)).