Quantum computing

This special issue of New Generation Computing consists of two invited papers and four fully reviewed papers. The contributions in this special issue represent state-of-the-art research ranging from basic theoretical works to advanced applications. In 1994, Peter Shor published a quantum algorithm for finding prime factors of composite integer more efficiently than is possible with the known algorithms for a current computer. Since the difficulty of the integer factoring is crucial for the security of RSA public key cryptography scheme, interest in quantmn computing suddenly blossomed. The power of quantum computing is based on several phenomena and laws of quantum physics such as complex probability amplitudes, quantum interference, quantum parallelism, quantum entanglement and the unitarity of quantum evolution. Quantum computing is a new interdisciplinary field emerging from interactions among the fields of computational and mathematical sciences, physics, and nanotechnology. And it is a significant challenge for information science to contribute to the development of new theories of computation and to deepen our understanding of physical worlds. In this special issue, we placed invited papers first. Other contributions are arranged arbitrarily. Here is a brief summary of the contributions: