QIC Abstracts

 Vol.19 No.1&12, February 1, 2019

Research Articles:

Toward an optimal quantum algorithm for polynomial factorization over finite fields (pp0001-0013)
          
Javad Dolizkani
We present a randomized quantum algorithm for polynomial factorization over finite fields. For polynomials of degree $n$ over a finite field $\F_q$, the average-case complexity of our algorithm is an expected $O(n^{1 + o(1)} \log^{2 + o(1)}q)$ bit operations. Only for a negligible subset of polynomials of degree $n$ our algorithm has a higher complexity of $O(n^{4/3 + o(1)} \log^{2 + o(1)}q)$ bit operations. This breaks the classical $3/2$-exponent barrier for polynomial factorization over finite fields \cite{guo2016alg}.

Teleportation via the entangled derivative of coherent state (pp0014-0022)
          
Anas Othman
Recently, David Yevick and I published an article [Othman, A. \& Yevick, D. Int J Theor Phys {\bf 57}, 2293 (2018)] about constructing a superposition of two nearly identical coherent states (near coherent state). We showed that this state becomes a superposition of a derivative state and a coherent state. Here, we use the definition of the derivative state to create the entangled derivative of coherent state (EDCS). We show that this state can be used to teleport qubits encoded in the near coherent states. The decoherence of EDCS is also studied. In addition, we propose an experimental scheme to produce the EDCS and to perform teleportation

Periodicity for the Fourier quantum walk on regular graphs (pp0023-0034)
          
Kei Saito
Quantum walks determined by the coin operator on graphs have been intensively studied. The typical examples of coin operator are the Grover and Fourier matrices. The periodicity of the Grover walk is well investigated. However, the corresponding result on the Fourier walk is not known. In this paper, we present a necessary condition for the Fourier walk on regular graphs to have the finite period. As an application of our result, we show that the Fourier walks do not have any finite period for some classes of regular graphs such as complete graphs, cycle graphs with selfloops, and hypercubes.

Grover-based Ashenhurst-Curtis decomposition using quantum language quipper (pp0035-0066)
          
Yiwei Li, Edison Tsai, Marek Perkowski, and Xiaoyu Song
Functional decomposition plays a key role in several areas such as system design, digital circuits, database systems, and Machine Learning. This paper presents a novel quantum computing approach based on Grover’s search algorithm for a generalized Ashenhurst-Curtis decomposition. The method models the decomposition problem as a search problem and constructs the oracle circuit based on the set-theoretic partition algebra. A hybrid quantum-based algorithm takes advantage of the quadratic speedup achieved by Grover’s search algorithm with quantum oracles for finding the minimum-cost decomposition. The method is implemented and simulated in the quantum programming language Quipper. This work constitutes the first attempt to apply quantum computing to functional decomposition.

Quantum complementarity and operator structures (pp0067-0083)
          
David W. Kribs, Jeremy Livick, Mike I. Nelson, Rajesh Perira, and Mizanur Rahaman
We establish operator structure identities for quantum channels and their error-correcting and private codes, emphasizing the complementarity relationship between the two perspectives. Relevant structures include correctable and private operator algebras, and operator spaces such as multiplicative domains and nullspaces of quantum channels and their complementary maps. For the case of privatizing to quantum states, we also derive dimension inequalities on the associated operator algebras that further quantify the trade-off between correction and privacy.

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