Transitions out of the ground space limit the performance of quantum adiabatic algorithms, while hardware imperfections impose stringent limitations on the circuit depth. We propose an adiabatic echo verification protocol which mitigates both coherent and incoherent errors, arising from non-adiabatic transitions and hardware noise, respectively. Quasi-adiabatically evolving forward and backward allows for an echo-verified measurement of any observable. In addition to mitigating hardware noise, our method uses positive-time dynamics only. Crucially, the estimator bias of the observable is reduced when compared to standard adiabatic preparation, achieving up to a quadratic improvement.

中文翻译：

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通过回波验证虚拟缓解相干非绝热跃迁

地面空间的过渡限制了量子绝热算法的性能，而硬件缺陷对电路深度施加了严格的限制。我们提出了一种绝热回波验证协议，该协议可以减轻分别由非绝热跃迁和硬件噪声引起的相干和不相干错误。准绝热向前和向后演化允许对任何可观测值进行回波验证测量。除了减轻硬件噪声之外，我们的方法仅使用正时间动态。至关重要的是，与标准绝热准备相比，可观测值的估计偏差减少了，从而实现了二次方的改进。