International Journal of Quantum Information, Special Issue on Noise, Information and Complexity at Quantum Scale

Noise and information, often believed to be conflicting notions, have a common denominator: stochastic processes. It is the attitude of the observer that turns a stochastic process into a noise source or into an information source. Underlying any stochastic process is randomness, which naturally leads to the notion of complexity. In recent years the exploration of these concepts has been pushed further down to the quantum scale, thus revealing a variety of new intriguing phenomena and potential applications. Hence, at a time when the physics community all around the world is grappling with the notions of noise, information and complexity from very different perspectives, it seemed timely and exciting to bring together scientists whose sole common denominator was stochastic processes in the quantum domain. The international meeting “Noise, Information and Complexity @ Quantum Scale”, was held on November 2nd–10th, 2007 at the E. Majorana Centre, Erice, Italy. We were honored by the participation of senior colleagues who contributed so much to the inception of this emerging discipline. We were also pleased by the attendance of many young scientists who are entering now the tumultuous arena of noise, information and complexity on the quantum scale. The aim – achieved beyond our expectations, – was to bring forward recent advances in the area of quantum statistical mechanics and quantum information with particular emphasis on the interdisciplinary aspects and methods. This special issue is a collection of some of the most significant contributions presented during the meeting. It focuses on specific quantum topics, like entanglement and quantum algorithms, but also on the quantum aspects of otherwise well established topics, like fluctuations and noise, measurement and error correction, control, complex structures and networks, communication, entropy, computational complexity, communication complexity, chaos and complex dynamics, stochastic resonance, statistics and thermodynamics. With this volume we hope to convey to the reader some of the excitement we witnessed during the meeting, where the cross dissemination of new ideas and tested techniques, in an informal and friendly environment, created a very stimulating atmosphere. The contributions (according to the subject of the meeting) are presented in a random way.