Observational Equivalence Using Schedulers for Quantum Processes

In the study of quantum process algebras, researchers have introduced different notions of equivalence between quantum processes like bisimulation or barbed congruence. However, there are intuitively equivalent quantum processes that these notions do not regard as equivalent. In this paper, we introduce a notion of equivalence named observational equivalence into qCCS. Since quantum processes have both probabilistic and nondeterministic transitions, we introduce schedulers that solve nondeterministic choices and obtain probability distribution of quantum processes. By definition, the restrictions of schedulers change observational equivalence. We propose some definitions of schedulers, and investigate the relation between the restrictions of schedulers and observational equivalence.Comment: In Proceedings QPL 2014, arXiv:1412.810

Potential Sputtering of Protons with Slow Multiply Charged Ions

Experimental findings of insulator sputtering with slow multiply charged ions are reviewed with particular emphasis on proton sputtering, including recent studies which pay attention not only to the yields, but also to the energy distributions of sputtered particles. A simplified scenario of multiply charged ion interaction with a solid surface is discussed, which consists of two stages, i.e., resonant charge transfers well above the surface (the stage I), and a violent collision with the surface transferring a major part of the potential energy (the stage II). A couple of processes relating to the sputtering in the stages I and II are discussed, which include a Coulomb explosion, an Auger stimulated desorption and its variations, and a pair-wise repulsion between charged species in the stage I. It is shown that the third process reproduces several important aspects of proton sputtering with multiply charged ions

Nonlinear wave propagation through cold plasma

Electromagnetic wave propagation through cold collision free plasma is studied using the nonlinear perturbation method. It is found that the equations can be reduced to the modified Kortweg-de Vries equation