Maximally entangled mixed states for qubit-qutrit systems
| Autor: | Samuel R. Hedemann, Paulo E. M. F. Mendonca, Marcelo A. Marchiolli |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
Semidefinite programming
Physics Pure mathematics Quantum Physics Optimization problem Rank (linear algebra) Degenerate energy levels FOS: Physical sciences Quantum entanglement 01 natural sciences 010305 fluids & plasmas Qubit 0103 physical sciences Qutrit Quantum Physics (quant-ph) 010306 general physics Degeneracy (mathematics) |
| Popis: | We consider the problems of maximizing the entanglement negativity of X-form qubit-qutrit density matrices with (i) a fixed spectrum and (ii) a fixed purity. In the first case, the problem is solved in full generality whereas, in the latter, partial solutions are obtained by imposing extra spectral constraints such as rank-deficiency and degeneracy, which enable a semidefinite programming treatment for the optimization problem at hand. Despite the technically-motivated assumptions, we provide strong numerical evidence that three-fold degenerate X states of purity $P$ reach the highest entanglement negativity accessible to arbitrary qubit-qutrit density matrices of the same purity, hence characterizing a sparse family of likely qubit-qutrit maximally entangled mixed states. 19 pages, 6 figures |
| Databáze: | OpenAIRE |
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