1203.5630 (Peng Xue)

Non-Markovian Decoherent Quantum Walks    [PDF]

Peng Xue

We study a non-Markovian decoherent quantum walk on a line. In the short time regime, the behavior of the quantum walk on a line with a non-Markovian dephaisng coin deviates from both idea quantum walks and random walks. The position variance starts oscillating from the first several steps and tends to be linear on time showing a diffusive spread in the long time limit, which is caused by the non-Markovian dephasing affecting on quantum correlations between quantum walker and his coin. We study both quantum discord and measurement-induced disturbance as measures of quantum correlations and observe that both of them show oscillating behavior in the short time regime and tends to zero in the long time limit. Therefore it proves that quantum correlations cause the characteristic quantum behavior of quantum walks and are affected by the non-Markvoian dephasing on the coin.

View original: http://arxiv.org/abs/1203.5630