Decoherence of a Double Quantum Dot Charge Qubit Approached with Redfield Equation

在这篇论文，我们调查一个双量点(DQD ) 的 decoherence 时间在通过解决 qubit 的动力学的三种洗澡的费用 qubit。qubit 的动力学与 Redfield 主人方程被调查。在欧姆的洗澡的 qubit 的 decoherence 时间把象实验的一样的数量级报导，这被显示出。当环境与在上被建模时 -- 欧姆的洗澡 qubit 的 decoherence 时间比试验性的结果短。并且当与亚 Ohmic 洗澡当模特儿时， qubit 的 decoherence 时间比试验性的结果长。

In this paper, we investigate the decoherence time of a double quantum dot （DQD） charge qubit in three kinds of baths through solving dynamics of the qubit. The dynamics of the qubit is investigated with Redfield master equation. It is shown that the decoherence time of the qubit in Ohmic bath has the same order of magnitude as the experiments reported. When the environment is modeled with the supra-Ohmic bath the decoherence time of the qubit is shorter than the experimental result. And when modeled with the sub-Ohmic bath the decoherence time of the qubit is longer than the experimental result.