Quantum Information Processing

Synthesis of multi-qudit hybrid and d-valued quantum logic circuits by decomposition

by Faisal Shah Khan

Theoretical Computer Science, Volume 367, Issue 3, 1 December 2006, Pages 336-346

10.1016/j.tcs.2006.09.006

Recent research in generalizing quantum computation from 2-valued qudits to d-valued qudits has shown practical... more Recent research in generalizing quantum computation from 2-valued qudits to d-valued qudits has shown practical advantages for scaling up a quantum computer. A further generalization leads to quantum computing with hybrid qudits where two or more qudits have different finite dimensions. Advantages of hybrid and d-valued gates (circuits) and their physical realizations have been studied in detail by Muthukrishnan and Stroud (Physical Review A, 052309, 2000), Daboul et al. (J. Phys. A: Math. Gen. 36 2525-2536, 2003), and Bartlett et al (Physical Review A, Vol.65, 052316, 2002). In both cases, a quantum computation is performed when a unitary evolution operator, acting as a quantum logic gate, transforms the state of qudits in a quantum system. Unitary operators can be represented by square unitary matrices. If the system consists of a single qudit, then Tilma et al (J.Phys. A: Math. Gen. 35 (2002) 10467-10501) have shown that the unitary evolution matrix (gate) can be synthesized in terms of its Euler angle parameterization. However, if the quantum system consists of multiple qudits, then a gate may be synthesized by matrix decomposition techniques such as QR factorization and the Cosine-sine Decomposition (CSD). In this article, we present a CSD based synthesis method for n qudit hybrid quantum gates, and as a consequence, derive a CSD based synthesis method for n qudit gates where all the qudits have the same dimension.

Synthesis of ternary quantum logic circuits by decomposition

by Faisal Shah Khan

Proceedings of the 7th International Symposium on Representations and Methodology of Future Computing Technologies RM2005

Recent research in multi-valued logic for quantum computing has shown practical advantages for scaling up a quantum... more Recent research in multi-valued logic for quantum computing has shown practical advantages for scaling up a quantum computer. Multivalued quantum systems have also been used in the framework of quantum cryptography, and the concept of a qudit cluster state has been proposed by generalizing the qubit cluster state. An evolutionary algorithm based synthesizer for ternary quantum circuits has recently been presented, as well as a synthesis method based on matrix factorization.In this paper, a recursive synthesis method for ternary quantum circuits based on the Cosine-Sine unitary matrix decomposition is presented

Analytic influence functionals for numerical Feynman integrals in most open quantum systems

by Nike Dattani

Different quantum phases have different computational power

by Mile Gu

Numerical Feynman integrals with physically inspired interpolation: Faster convergence and significant reduction of computational cost

by Nike Dattani

2012 - Published in AIP Advances

Entanglement-Assisted Quantum Convolutional Coding

by Mark Wilde

Physical Review A 81, 042333 (2010)

We show how to protect a stream of quantum information from decoherence induced by a noisy quantum communication... more We show how to protect a stream of quantum information from decoherence induced by a noisy quantum communication channel. We exploit preshared entanglement and a convolutional coding structure to develop a theory of entanglement-assisted quantum convolutional coding. Our construction produces a Calderbank-Shor-Steane (CSS) entanglement-assisted quantum convolutional code from two arbitrary classical binary convolutional codes. The rate and error-correcting properties of the classical convolutional codes directly determine the corresponding properties of the resulting entanglement-assisted quantum convolutional code. We explain how to encode our CSS entanglement-assisted quantum convolutional codes starting from a stream of information qubits, ancilla qubits, and shared entangled bits.

A high stability beam-scanning confocal optical microscope for low temperature operation

by Fabio Grazioso

Co-authored with Brian R. Patton, Jason M. Smith. Published in Review of Scientific Instruments, vol. 81, p. 093705, year 2010

We report on the design and performance of a high stability scanning confocal microscope for optical microscopy at low... more We report on the design and performance of a high stability scanning confocal microscope for optical microscopy at low temperatures. By scanning the beam in a cold objective lens system, we achieve wide fields of view without compromising image quality. Photoluminescence from single nitrogen-vacancy centers in high purity diamond is used to illustrate the imaging and stability performance of the microscope.

Converging Technologies: The Future of the Global Information Society

by Christopher Altman

First Committee chair report to the UN General Assembly, RSA Information Security Award for Outstanding Achievement (2004).

"Christopher Altman, Chairman of the UNISCA First Committee on Disarmament and International Security, was recently selected as recipient of the RSA Information Security Award for Outstanding Achievement in Government Policy for his report to the General Assembly, "Converging Technologies: The Future of the Global Information Society."

"The RSA Conference and Awards is the world's most prestigious international information security conference for organizations that deploy, develop or investigate security or cryptography."

"Previous RSA Keynote speakers and Awards Recipients include Bill Gates, Microsoft Corporation, US Congressman Tom Davis, and Richard Clarke, former White House Security Advisor. "

The complex web of the global information grid will undergo explosive changes over coming decades. As advances in... more The complex web of the global information grid will undergo explosive changes over coming decades. As advances in science and technology converge, a myriad array of discoveries in biotechnology, nanotechnology and information technology will produce unpredictable effects that must be accounted for in any estimate of what the world will look like in this future. A strategically important feature of this world will be the emerging trend of information warfare. Though still immature at present day, this trend will become increasingly dominant in the years to come. The information warfare of tomorrow will be radically different from its prototype today. No longer will it be confined to the mainframes of the Internet or to corporate databases: the battleground of the future will draw into its scope the scientific advances being made today in bio and nano technologies. The divisions between man and machine will blur. When networked technologies are ubiquitous, a state-sponsored attack on electronic networks can have far-reaching, and devastating, physical consequences.