Determinism in the one-way model

We introduce a flow condition on open graph states (graph states with inputs and outputs) which guarantees globally deterministic behavior of a class of measurement patterns defined over them. Dependent Pauli corrections are derived for all such patterns, which equalize all computation branches, and only depend on the underlying entanglement graph and its choice of inputs and outputs. The class of patterns having flow is stable under composition and tensorization, and has unitary embeddings as realizations. The restricted class of patterns having both flow and reverse flow, supports an operation of adjunction, and has all and only unitaries as realizations.Comment: 8 figures, keywords: measurement based quantum computing, deterministic computing; Published version, including a new section on circuit decompositio

Generalized Flow and Determinism in Measurement-based Quantum Computation

We extend the notion of quantum information flow defined by Danos and Kashefi for the one-way model and present a necessary and sufficient condition for the deterministic computation in this model. The generalized flow also applied in the extended model with measurements in the X-Y, X-Z and Y-Z planes. We apply both measurement calculus and the stabiliser formalism to derive our main theorem which for the first time gives a full characterization of the deterministic computation in the one-way model. We present several examples to show how our result improves over the traditional notion of flow, such as geometries (entanglement graph with input and output) with no flow but having generalized flow and we discuss how they lead to an optimal implementation of the unitaries. More importantly one can also obtain a better quantum computation depth with the generalized flow rather than with flow. We believe our characterization result is particularly essential for the study of the algorithms and complexity in the one-way model.Comment: 16 pages, 10 figure

Generalized Flow and Determinism in Measurement-based Quantum Computation

We extend the notion of quantum information flow defined by Danos and Kashefi for the one-way model and present a necessary and sufficient condition for the deterministic computation in this model. The generalized flow also applied in the extended model with measurements in the X-Y, X-Z and Y-Z planes. We apply both measurement calculus and the stabiliser formalism to derive our main theorem which for the first time gives a full characterization of the deterministic computation in the one-way model. We present several examples to show how our result improves over the traditional notion of flow, such as geometries (entanglement graph with input and output) with no flow but having generalized flow and we discuss how they lead to an optimal implementation of the unitaries. More importantly one can also obtain a better quantum computation depth with the generalized flow rather than with flow. We believe our characterization result is particularly essential for the study of the algorithms and complexity in the one-way model.Comment: 16 pages, 10 figure

Delocalization power of global unitary operations on quantum information

We investigate how originally localized two pieces of quantum information represented by a tensor product of two unknown qudit states are delocalized by performing two-qudit global unitary operations. To characterize the delocalization power of global unitary operations on quantum information, we analyze the necessary and sufficient condition to deterministically relocalize one of the two pieces of quantum information to its original Hilbert space by using only LOCC. We prove that this LOCC one-piece relocalization is possible if and only if the global unitary operation is local unitary equivalent to a controlled-unitary operation. The delocalization power and the entangling power characterize different non-local properties of global unitary operations.Comment: 14 pages, 1 figur

Information Theoretically Secure Hypothesis Test for Temporally Unstructured Quantum Computation (Extended Abstract)

The efficient certification of classically intractable quantum devices has been a central research question for some time. However, to observe a "quantum advantage", it is believed that one does not need to build a large scale universal quantum computer, a task which has proven extremely challenging. Intermediate quantum models that are easier to implement, but which also exhibit this quantum advantage over classical computers, have been proposed. In this work, we present a certification technique for such a sub-universal quantum server which only performs commuting gates and requires very limited quantum memory. By allowing a verifying client to manipulate single qubits, we exploit properties of measurement based blind quantum computing to give them the tools to test the "quantum superiority" of the server

The influences of employees' emotions and cognition on IT adoption: Some perspectives from Iran

This paper presents an extended model of individuals’ reactions to IT implementation initiatives. The aim is to explore the relationship between an employee’s cognitive appraisal of an IT initiative, their emotional response and the processes they undergo when faced with difficulties in accepting IT adoption and change in an organizational setting. The paper presents the results of an interpretive case study based in Iran. According to the findings of the study, employees’ evaluations of a new IT initiative can become an obstacle to change. The paper’s first contribution is to provide a deeper understanding of the effects of an IT implementation on individuals’ emotions and cognition. The second contribution is the use of the extended model in a real organizational setting in Iran, a country in which the importance of employee’s reactions to technology change has never been considered as crucial

Проект энергоблока АЭС с реактором типа ВВЭР-600

Объектом исследования является проект энергоблока с реактором ВВЭР-600. Цель работы – расчет реакторной установки, парогенератора, принципиальной схемы ПТУ методом энергетического баланса, конденсационной установки и регенеративного подогревателя низкого давления поверхностного типа. В процессе работы рассчитаны и спроектированы основные составляющие ядерной энергетической установки: реакторная установка, парогенератор, расчет на прочность парогенераторной установки.The object of research is the development of a power unit with VVER-600. The purpose of the work – calculation of reactor plant, steam generator schematic diagrams of the PTU method energy balance of the condensing unit and the regenerative heater low pressure surface type. In the process, designed the basic components of a nuclear power plant: reactor, steam generator, calculating the strength of steam plant. Final qualifying work is executed in a text editor Microsoft word 2010, graphs are constructed in a workbook in Microsoft Excel 2010, and the drawings made with the program Corel DRAWX5, equation editor Math CAD 15

Unconditionally verifiable blind computation

Blind Quantum Computing (BQC) allows a client to have a server carry out a quantum computation for them such that the client's input, output and computation remain private. A desirable property for any BQC protocol is verification, whereby the client can verify with high probability whether the server has followed the instructions of the protocol, or if there has been some deviation resulting in a corrupted output state. A verifiable BQC protocol can be viewed as an interactive proof system leading to consequences for complexity theory. The authors, together with Broadbent, previously proposed a universal and unconditionally secure BQC scheme where the client only needs to be able to prepare single qubits in separable states randomly chosen from a finite set and send them to the server, who has the balance of the required quantum computational resources. In this paper we extend that protocol with new functionality allowing blind computational basis measurements, which we use to construct a new verifiable BQC protocol based on a new class of resource states. We rigorously prove that the probability of failing to detect an incorrect output is exponentially small in a security parameter, while resource overhead remains polynomial in this parameter. The new resource state allows entangling gates to be performed between arbitrary pairs of logical qubits with only constant overhead. This is a significant improvement on the original scheme, which required that all computations to be performed must first be put into a nearest neighbour form, incurring linear overhead in the number of qubits. Such an improvement has important consequences for efficiency and fault-tolerance thresholds.Comment: 46 pages, 10 figures. Additional protocol added which allows arbitrary circuits to be verified with polynomial securit