Switching of Geometric Phase in Degenerate Systems
arXiv:cond-mat/0007204 · doi:10.1016/S0375-9601(00)00425-4
Abstract
The geometric and open path phases of a four-state system subject to time varying cyclic potentials are computed from the Schrödinger equation. Fast oscillations are found in the non-adiabatic case. For parameter values such that the system possesses degenerate levels, the geometric phase becomes anomalous, undergoing a sign switch. A physical system to which the results apply is a molecular dimer with two interacting electrons. Additionally, the sudden switching of the geometric phase promises to be an efficient control in two-qubit quantum computing.
15 pages, 4 figures,accepted by Physics Letters A (2000)