论文标题
单个值的实时自适应估计的破碎时间尺度
Real-time adaptive estimation of decoherence timescales for a single qubit
论文作者
论文摘要
表征量子一致性生存的时间对于任何实施量子位，记忆和传感器至关重要。确定量子系统的分解速率的通常方法涉及一套实验，以探测该参数的整个预期范围，并在后处理中提取所得估计。在这里，我们基于简单的分析更新规则提出了一种自适应多参数贝叶斯方法，以估算关键的分解时间标准（$ t_1 $，$ t_2^*$和$ t_2 $）以及实时使用量子系统的相应衰减指标，并使用先前的实验中获得量子系统的相应衰减指标。与曲线拟合的标准方案相比，这种方法将达到给定的不确定性的时间减少到一个数量级的因素所需的时间。通过对灵敏度进行优化而不是差异，可以实现一个因子$ \ sim 2 $的进一步加速。
Characterising the time over which quantum coherence survives is critical for any implementation of quantum bits, memories and sensors. The usual method for determining a quantum system's decoherence rate involves a suite of experiments probing the entire expected range of this parameter, and extracting the resulting estimation in post-processing. Here we present an adaptive multi-parameter Bayesian approach, based on a simple analytical update rule, to estimate the key decoherence timescales ($T_1$, $T_2^*$ and $T_2$) and the corresponding decay exponent of a quantum system in real time, using information gained in preceding experiments. This approach reduces the time required to reach a given uncertainty by a factor up to an order of magnitude, depending on the specific experiment, compared to the standard protocol of curve fitting. A further speed-up of a factor $\sim 2$ can be realised by performing our optimisation with respect to sensitivity as opposed to variance.
