Zheng Xin, Dolde Jonathan, Cambria Matthew C, Lim Hong Ming, Kolkowitz Shimon
Department of Physics, University of Wisconsin-Madison, Madison, WI, 53706, USA.
Department of Physics, University of California, Berkeley, CA, 94720, USA.
Nat Commun. 2023 Aug 12;14(1):4886. doi: 10.1038/s41467-023-40629-8.
Einstein's theory of general relativity predicts that a clock at a higher gravitational potential will tick faster than an otherwise identical clock at a lower potential, an effect known as the gravitational redshift. Here we perform a laboratory-based, blinded test of the gravitational redshift using differential clock comparisons within an evenly spaced array of 5 atomic ensembles spanning a height difference of 1 cm. We measure a fractional frequency gradient of [ - 12.4 ± 0. 7 ± 2. 5] × 10/cm, consistent with the expected redshift gradient of - 10.9 × 10/cm. Our results can also be viewed as relativistic gravitational potential difference measurements with sensitivity to mm scale changes in height on the surface of the Earth. These results highlight the potential of local-oscillator-independent differential clock comparisons for emerging applications of optical atomic clocks including geodesy, searches for new physics, gravitational wave detection, and explorations of the interplay between quantum mechanics and gravity.
爱因斯坦的广义相对论预测，处于较高引力势的时钟会比处于较低势的相同时钟走得更快，这种效应被称为引力红移。在此，我们利用跨越1厘米高度差的5个原子系综的均匀间隔阵列内的差分时钟比较，进行了基于实验室的引力红移盲测。我们测量到的分数频率梯度为[ - 12.4 ± 0. 7 ± 2. 5] × 10⁻¹⁵/厘米，与预期的红移梯度 - 10.9 × 10⁻¹⁵/厘米一致。我们的结果也可被视为对相对论引力势差的测量，对地球表面毫米尺度的高度变化具有敏感性。这些结果凸显了与本地振荡器无关的差分时钟比较在光学原子钟新兴应用中的潜力，包括大地测量、新物理探索、引力波探测以及量子力学与引力相互作用的研究。
