Quantum systems can be used to measure various quantities in their environment with high precision. Often, however, their sensitivity is limited by the decohering effects of this same environment. Dynamical decoupling schemes are widely used to filter environmental noise from signals, but their performance is limited by the spectral properties of the signal and noise at hand. Quantum error correction schemes have therefore emerged as a complementary technique without the same limitations. To date, however, they have failed to correct the dominant noise type in many quantum sensors, which couples to each qubit in a sensor in the same way as the signal. Here we show how quantum error correction can correct for such noise, which dynamical decoupling can only partially address. Whereas dynamical decoupling exploits temporal noise correlations in signal and noise, our scheme exploits spatial correlations. We give explicit examples in small quantum devices and demonstrate a method by which error-correcting codes can be tailored to their noise.

量子系统可用于在其环境中高精度测量各种量。但是，通常，它们的灵敏度受到相同环境的去相干效应的限制。动态去耦方案已广泛用于从信号中滤除环境噪声，但其性能受到信号和手头噪声的频谱特性的限制。因此，量子误差校正方案已作为一种互补技术出现，而没有相同的限制。然而，迄今为止，他们尚未纠正许多量子传感器中的主要噪声类型，该噪声以与信号相同的方式耦合到传感器中的每个量子位。在这里，我们展示了量子误差校正如何校正这种噪声，而这种动态去耦只能部分解决。动态解耦利用信号和噪声中的时间噪声相关性，而我们的方案利用空间相关性。我们在小型量子设备中给出了明确的示例，并演示了一种可以针对其噪声量身定制纠错码的方法。