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Faculty publications – Physics

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KLEIN PARADOX

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Articles 1 - 4 of 4

Full-Text Articles in Physics

Pair Creation For Bosons In Electric And Magnetic Fields, Q Z. Lv, A C. Su, M Jiang, Rainer Grobe, Qichang Su Feb 2013

Pair Creation For Bosons In Electric And Magnetic Fields, Q Z. Lv, A C. Su, M Jiang, Rainer Grobe, Qichang Su

Faculty publications – Physics

By solving the quantum field theoretical version of the Klein-Gordon equation numerically, we study the creation process for charged boson-antiboson pairs in static electric and magnetic fields. The fields are perpendicular to each other and spatially localized along the same direction, which permits us to study the crucial impact of the magnetic field's spatial extension on dynamics. If its width is comparable to that of the electric field, we find a magnetically induced Lorentz suppression of the pair-creation process. When the width is increased such that the created bosons can revisit the interaction region, we find a region of exponential …


Pair Creation Rates For One-Dimensional Fermionic And Bosonic Vacua, T Cheng, M R. Ware, Q Su, Rainer Grobe Dec 2009

Pair Creation Rates For One-Dimensional Fermionic And Bosonic Vacua, T Cheng, M R. Ware, Q Su, Rainer Grobe

Faculty publications – Physics

We compare the creation rates for particle-antiparticle pairs produced by a supercritical force field for fermionic and bosonic model systems. The rates obtained from the Dirac and Klein-Gordon equations can be computed directly from the quantum-mechanical transmission coefficients describing the scattering of an incoming particle with the supercritical potential barrier. We provide a unified framework that shows that the bosonic rates can exceed the fermionic ones, as one could expect from the Pauli-exclusion principle for the fermion system. This imbalance for small but supercritical forces is associated with the occurrence of negative bosonic transmission coefficients of arbitrary size for the …


Unitary And Nonunitary Approaches In Quantum Field Theory, K D. Lamb, Christopher C. Gerry, Rainer Grobe Jan 2007

Unitary And Nonunitary Approaches In Quantum Field Theory, K D. Lamb, Christopher C. Gerry, Rainer Grobe

Faculty publications – Physics

We use a simplified essential state model to compare two quantum field theoretical approaches to study the creation of electron-positron pairs from the vacuum. In the unitary approach the system is characterized by a state with different numbers of particles that is described by occupation numbers and evolves with conserved norm. The nonunitary approach can predict the evolution of wave functions and density operators with a fixed number of particles but time-dependent norms. As an example to illustrate the differences between both approaches, we examine the degree of entanglement for the Klein paradox, which describes the creation of an electron-positron …


Timing Of Pair Production In Time-Dependent Force Fields, Christopher C. Gerry, Q Su, Rainer Grobe Oct 2006

Timing Of Pair Production In Time-Dependent Force Fields, Christopher C. Gerry, Q Su, Rainer Grobe

Faculty publications – Physics

We examine the creation and annihilation dynamics for electron-positron pairs in a time-dependent but subcritical electric force using a simplified model system. Numerical and semianalytical solutions to computational quantum field theory show that despite the continuity of the quantum field operator in time, the actual number of created particles can change in a discontinuous way if the field changes abruptly. The number of permanently created particles after the pulse, however, increases continuously with the duration of the electric field pulse, suggesting a transition from an exclusive annihilation to a creation regime.