Turku Center for Quantum Physics, Department of Physics and Astronomy, Turku, FIN-20014, Turun yliopisto, Finland.
Faculdade de Ciências, UNESP - Universidade Estadual Paulista, Bauru, SP, 17033-360, Brazil.
Sci Rep. 2017 Aug 21;7(1):8367. doi: 10.1038/s41598-017-08457-1.
We study the symmetry properties in the dynamics of quantum correlations for two-qubit systems in one-sided noisy channels, with respect to a switch in the location of noise from one qubit to the other. We consider four different channel types, namely depolarizing, amplitude damping, bit-flip, and bit-phase-flip channel, and identify the classes of initial states leading to symmetric decay of entanglement, non-locality and discord. Our results show that the symmetric decay of quantum correlations is not directly linked to the presence or absence of symmetry in the initial state, while it does depend on the type of correlation considered as well as on the type of noise. We prove that asymmetric decay can be used to infer, in certain cases, characteristic properties of the channel. We also show that the location of noise may lead to dramatic changes in the persistence of phenomena such as entanglement sudden death and time-invariant discord.
我们研究了在单边噪声信道中,两个量子比特系统的量子相关性动力学的对称性质,相对于噪声从一个量子比特到另一个量子比特位置的切换。我们考虑了四种不同的信道类型,即去极化、幅度阻尼、位翻转和位相翻转信道,并确定了导致纠缠、非局域性和失谐对称衰减的初始态类。我们的结果表明,量子相关性的对称衰减与初始态的对称性无关,而是取决于所考虑的相关性类型以及噪声类型。我们证明,在某些情况下,不对称衰减可用于推断信道的特征性质。我们还表明,噪声的位置可能导致诸如纠缠突然死亡和时间不变失谐等现象的持久性发生剧烈变化。