2011/07/31 by A. R. Vieira, J. G. G. de Oliveira Junior, J. G. Peixoto de Faria +1 · 1 citation
Computer Science · Physics and Astronomy · #Concurrence #Conic section #Diagram #Dynamics (music) #Limiting #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum entanglement #Quantum many-body systems #Qubit #RADIUS #quant-ph
paper · pdf · doi:10.1007/s13538-013-0174-6
11 pages, 21 figures. Brazilian Journal of Physics (2014)
openalex publication_date 2013/12/19 · arxiv created 2013/12/22 · arxiv updated 2015/03/19 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We report on the geometric character of the entanglement dynamics of to pairs of qubits evolving according to the double Jaynes-Cummings model. We show that the entanglement dynamics for the initial states |ψ0> = Cosα |1 0> + Sinα |0 1> and |ϕ0> = Cosα |1 1> + Sinα |0 0> cover 3-dimensional surfaces in the diagram Cij\timesCik\timesCil, where Cmn stands for the concurrence between the qubits m and n, varying 0≤α≤π/2. In the first case projections of the surfaces on a diagram Cij\timesCkl are conics. In the second case the curves can be more complex. We relate those conics with a measurable quantity, the \it predictability.We also derive inequalities limiting the sum of the squares of the concurrence of every bipartition and show that sudden death of entanglement is intimately connected to the size of the radius of a hyper-sphere.