Dyson-Schwinger Equations with a Parameterized Metric

We construct and solve the Dyson-Schwinger equation (DSE) of quark propagator with a parameterized metric, which connects the Euclidean metric with the Minkowskian one. We show, in some models, the Minkowskian vacuum is different from the Euclidean vacuum. The usual analytic continuation of Green function does not make sense in these cases. While with the algorithm we proposed and the quark-gluon vertex ansatz which preserves the Ward-Takahashi identity, the vacuum keeps being unchanged in the evolution of the metric. In this case, analytic continuation becomes meaningful and can be fully carried out.Comment: 10 pages, 7 figures. To appear in Physical Review

The Practical Significance of Constructing the Big Shenyang Touring Circle

Six items about the practical significance of constructing the big touring circle have been briefly presented in this paper; meanwhile, the detailed analysis of the practical significance has also been made in each item. Thus constructing the major economy circle centered on Shenyang city within the North-East economy circle can be regarded as the most pressing matter of the moment. Key words: constructing, the big touring circle, the practical significance Résumé: A propos de la signification pratiquée par la construction du grand cercle touristique, il y a six parties présentées dans cet essai. D’ailleurs nous faisons encore une analyse détaillée sur cette signification pratique à la fin de chaque partie. Par conséquent, la construction centralisée à Shenyang du majeur cercle économique qui est en dedans du cercle économique Nord-Est est considérée comme affaire la plus urgente en ce moment. Mots-Clés: construction, grand cercle touristique, signification pratiqu

Quantum computing through electron propagation in the edge states of quantum spin Hall systems

We propose to implement quantum computing based on electronic spin qubits by controlling the propagation of the electron wave packets through the helical edge states of quantum spin Hall systems (QSHs). Specfically, two non-commutative single-qubit gates, which rotate a qubit around z and y axes, can be realized by utilizing gate voltages either on a single QSH edge channel or on a quantum point contact structure. The more challenging two-qubit controlled phase gate can be implemented through the on-demand capacitive Coulomb interaction between two adjacent edge channels from two parallel QSHs. As a result, a universal set of quantum gates can be achieved in an all-electrical way. The fidelity and purity of the two-qubit gate are calculated with both time delay and finite width of the wave packets taken into consideration, which can reach high values with the existing high-quality single electron source