Biblioteca Digital de Teses e Dissertações da UFCG 1 Biblioteca Digital de Teses e Dissertações da USP 1

Bomfim, Diego Marcel Costa 1 MEDEIROS, Rex Antonio da Costa 1

Tese 2

Inglês 1 Português 1

Canais Quânticos 1 Canal Quântico Ruidoso 1 Capacidade Erro-Zero de Canais Quânticos - CEZQ 1 Competência tributária 1 Competência tributária da união 1 Direito tributário 1 Mais ... Engenharia Elétrica. 1 Erro-Zero de Canais Discretos 1 Erro-Zero de Canais Quânticos 1 Fiscalização tributária 1 In this thesis, we generalise Shannon’s zero-error capacity of discrete memoryless channels to quantum channels. We propose a new kind of capacity for transmitting classical information through a quantum channel. The quantum zero-error capacity (QZEC) is defined as being the maximum amount of classical information per channel use that can be sent over a noisy quantum channel, with the restriction that the probability of error must be equal to zero. The communication protocol restricts codewords to tensor products of input quantum states, whereas collective measurements can be performed between several channel outputs. Hence, our communication protocol is similar to the Holevo-Schumacher-Westmoreland protocol. We reformulate the problem of finding the QZEC in terms of graph theory. This equivalent definition allows us to demonstrate some properties of ensembles of quantum states and measurements attaining the QZEC. We show that the capacity of ad-dimensional quantum channel can always be achieved by using an ensemble of at mostd pure quantum states, and collective von Neumann measurements are necessary and sufficient to attain the channel capacity. We discuss whether the QZEC is a non-trivial generalisation of the classical zero-error capacity. By non-trivial we mean that there exist quantum channels requiring two or more channel uses in order to reach the capacity, and the capacity can only be attained by using ensembles of non-orthogonal quantum states at the channel input. We also calculate the QZEC of some quantum channels. We show that finding the QZEC of classical-quantum channels is a purely classical problem. In particular, we exhibit a quantum channel for which we claim the QZEC can only be reached by a set of non-orthogonal states. If the conjecture holds, it is possible to give an exact solution for the capacity, and construct an error-free quantum block code reaching the capacity. Finally, we demonstrate that the QZEC is upper bounded by the Holevo-Schumacher-Westmoreland capacity. 1 Intervenção do estado (direito econômico) 1 Protocolo de Holevo-Schumacher-Westmoreland 1 Quantum Channels 1 Telecomunicações 1 The main goal of this thesis is to investigate the constitutional limits on the use of non-fiscal purpose tax laws 1 a model of decision making protocol is presented for use a mean of control by the Judiciary Branch of the non-fiscal purpose tax 1 and analyzes the numerous methods proposed for such classification. The thesis suggests that non-fiscal purpose tax laws must be identified by their p 1 as interpreted by those responsible for applying the law. The second part investigates the constitutional basis that legitimates the use of non-fiscal 1 as well as to the limits involving the tax species provided by the Federal Constitution. Finally 1 contributing 1 highlighting the principles of equality and proportionality. 1 the non-fiscal purpose tax laws are compared to the constitutional limits on taxation 1 the thesis was divided into four parts. The first part focuses in discussing the importance of segregation of tax laws in two groups: fiscal and non-f 1 to the conflict between regulatory competence and fiscal competence 1 to the constitutional concept of tax 1 to the development of methods that allow a more precise control of these instruments by the Judiciary Branch. To achieve such goal 1 with originality 1 Ver todos ... menos ...