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Full-Text Articles in Atomic, Molecular and Optical Physics
Suppression Of Pair Creation Due To A Steady Magnetic Field, W Su, M Jiang, Z Q. Lv, Rainer Grobe, Qichang Su
Suppression Of Pair Creation Due To A Steady Magnetic Field, W Su, M Jiang, Z Q. Lv, Rainer Grobe, Qichang Su
Faculty publications – Physics
We investigate the electron-positron pair creation process in a supercritical static electric field in the presence of a static magnetic field that is perpendicular. If both fields vary spatially in one direction the dynamics can be reduced to a set of one-dimensional systems. Using a generalized computational quantum field theoretical procedure, we calculate the time dependence of the spatial density for the created electrons. In the presence of the magnetic field, a significant amount of suppression of pair creation is observed in the simulations and confirmed by an analytical analysis for the limits of short-range fields and long interaction times. …
Pair Creation Enhancement Due To Combined External Fields, M Jiang, W Su, Z Q. Lv, X Lu, Y J. Li, Rainer Grobe, Qichang Su
Pair Creation Enhancement Due To Combined External Fields, M Jiang, W Su, Z Q. Lv, X Lu, Y J. Li, Rainer Grobe, Qichang Su
Faculty publications – Physics
We study the creation of electron-positron pairs from the vacuum induced by a combination of a static electric field and an alternating field. We find that the overall pair production can be increased by two orders of magnitude compared to the yields associated with each field individually. We examine the interesting case where both fields are spatially localized, permitting us to examine the time evolution of the spatial density for the created particle pairs. We find that there are a variety of competing mechanisms that contribute to the total yield.
Local And Nonlocal Spatial Densities In Quantum Field Theory, R E. Wagner, M R. Ware, E V. Stefanovich, Qichang Su, Rainer Grobe
Local And Nonlocal Spatial Densities In Quantum Field Theory, R E. Wagner, M R. Ware, E V. Stefanovich, Qichang Su, Rainer Grobe
Faculty publications – Physics
We use a one-dimensional model system to compare the predictions of two different yardsticks to compute the position of a particle from its quantum field theoretical state. Based on the first yardstick (defined by the Newton-Wigner position operator), the spatial density can be arbitrarily narrow, and its time evolution is superluminal for short time intervals. Furthermore, two spatially distant particles might be able to interact with each other outside the light cone, which is manifested by an asymmetric spreading of the spatial density. The second yardstick (defined by the quantum field operator) does not permit localized states, and the time …