134,936 research outputs found
Stability of quantum states of finite macroscopic systems
We study the stabilities of quantum states of macroscopic systems, against
noises, against perturbations from environments, and against local
measurements. We show that the stabilities are closely related to the cluster
property, which describes the strength of spatial correlations of fluctuations
of local observables, and to fluctuations of additive operators. The present
theory has many applications, among which we discuss the mechanism of phase
transitions in finite systems and quantum computers with a huge number of
qubits.Comment: Proceedings of the Japan-Italy Joint Waseda Workshop on "Fundamental
Problems in Quantum Mechanics", 27-29 September, 2001, Tokyo, Japan. (Edited
by S. Tasaki, to be published from World Scientific, 2002) 7 pages, no
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Four Decades of Computing in Subnuclear Physics - from Bubble Chamber to LHC
This manuscript addresses selected aspects of computing for the
reconstruction and simulation of particle interactions in subnuclear physics.
Based on personal experience with experiments at DESY and at CERN, I cover the
evolution of computing hardware and software from the era of track chambers
where interactions were recorded on photographic film up to the LHC experiments
with their multi-million electronic channels
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