The Roles of a Quantum Channel on a Quantum State
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When a quantum state undergoes a quantum channel, the state will be inevitably influenced. In general, the fidelity of the state is reduced, so is the entanglement if the subsystems go through the channel. However, the influence on the coherence of the state is quite different. Here we present some state-independent quantities to describe to what degree the fidelity, the entanglement and the coherence of the state are influenced. As applications, we consider some quantum channels on a qubit and find that the infidelity ability monotonically depends on the decay rate, but in usual the decoherence ability is not the case and strongly depends on the channel.
KeywordsQuantum channel Decoherence Fidelity
Yu thanks Xiaoguang Wang for valuable suggestion. This work was supported by the National Natural Science Foundation of China, under Grants No. 11375036 and 11175033 and by the Fundamental Research Funds of the Central Universities, under Grant No. DUT12LK42.
- 15.Yu, C.-s., Zhang, Y., Zhao, H.: unpublished Google Scholar