Dynamical correlations of negativity and entropy for pure and mixed states in two coupled quartic oscillators |
| |
Authors: | Xi-Wen Hou Ming-Fang Wan Zhong-Qi Ma |
| |
Institution: | (1) Information Sciences, Tokyo University of Science, Yamazaki 2641, 278-8510 Noda, Japan;(2) Mathematical Physics, Steklov Mathematical Institute, Gubkin St 8, 119991 Moscow, Russia; |
| |
Abstract: | Various measures of entanglement have triggered considerable interest in the
relationship between entanglement measures and other
well-known quantities. As a demonstration, the dynamical
correlation of negativity and entropy is studied in two
coupled quartic oscillators for initial pure and mixed states that
are respectively taken to be the products and mixed density
matrices of coherent states and squeezed states on each
oscillator. The correlation with energy is also considered.
It is shown that for the initial pure states with a
small magnitude, two negativities are
positively correlated with the von Neumann entropy while they are anti-correlated with
the energy of each oscillator in the weak coupling regime. For mixed states
with a small magnitude the two negativities and the mutual entropy exhibit dominantly
positive correlation, whereas those three quantities are
dominantly anti-correlated with the sum of energies of two
oscillators in the case of weak interactions. Such correlation behaviors in the mixed
state with small magnitudes are most striking at the same step in
maximal and minimal values and in oscillation. The differences in
entropies and negativities between coherent states and squeezed
states are discussed. These are useful for quantum
entanglement and quantum information processing. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|