Duality quantum computer and the efficient quantum simulations

• Published in: Quantum information processing Vol. 15; no. 3; pp. 1189 - 1212
• Main Authors: Wei, Shi-Jie, Long, Gui-Lu
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.03.2016
• Subjects: Data Structures and Information Theory; Mathematical Physics; Physics; Physics and Astronomy; Quantum Computing; Quantum Information Technology; Quantum Physics; Spintronics; Duality quantum computer; Quantum combiner; Duality computing mode; Duality computer; Linear combination of unitary operators; Quantum divider; Duality parallelism; Quantum simulation
• ISSN: 1570-0755; 1573-1332
• DOI: 10.1007/s11128-016-1263-6

Duality quantum computing is a new mode of a quantum computer to simulate a moving quantum computer passing through a multi-slit. It exploits the particle wave duality property for computing. A quantum computer with n qubits and a qudit simulates a moving quantum computer with n qubits passing through a d -slit. Duality quantum computing can realize an arbitrary sum of unitaries and therefore a general quantum operator, which is called a generalized quantum gate. All linear bounded operators can be realized by the generalized quantum gates, and unitary operators are just the extreme points of the set of generalized quantum gates. Duality quantum computing provides flexibility and a clear physical picture in designing quantum algorithms, and serves as a powerful bridge between quantum and classical algorithms. In this paper, after a brief review of the theory of duality quantum computing, we will concentrate on the applications of duality quantum computing in simulations of Hamiltonian systems. We will show that duality quantum computing can efficiently simulate quantum systems by providing descriptions of the recent efficient quantum simulation algorithm of Childs and Wiebe (Quantum Inf Comput 12(11–12):901–924,  2012 ) for the fast simulation of quantum systems with a sparse Hamiltonian, and the quantum simulation algorithm by Berry et al. (Phys Rev Lett 114:090502,  2015 ), which provides exponential improvement in precision for simulating systems with a sparse Hamiltonian.