Wiens E, Nevsky A Yu, Schiller S
Institut für Experimentalphysik, Heinrich-Heine-Universtität Düsseldorf, 40225 Düsseldorf, Germany.
Phys Rev Lett. 2016 Dec 30;117(27):271102. doi: 10.1103/PhysRevLett.117.271102. Epub 2016 Dec 29.
In order to investigate the long-term dimensional stability of matter, we have operated an optical resonator fabricated from crystalline silicon at 1.5 K continuously for over one year and repeatedly compared its resonance frequency f_{res} with the frequency of a GPS-monitored hydrogen maser. After allowing for an initial settling time, over a 163-day interval we found a mean fractional drift magnitude |f_{res}^{-1}df_{res}/dt|<1.4×10^{-20}/s. The resonator frequency is determined by the physical length and the speed of light and we measure it with respect to the atomic unit of time. Thus the bound rules out, to first order, a hypothetical differential effect of the Universe's expansion on rulers and atomic clocks. We also constrain a hypothetical violation of the principle of local position invariance for resonator-based clocks and derive bounds for the strength of space-time fluctuations.
为了研究物质的长期尺寸稳定性，我们让一个由晶体硅制成的光学谐振器在1.5K下连续运行了一年多，并反复将其共振频率(f_{res})与全球定位系统监测的氢微波激射器的频率进行比较。在经过初始稳定时间后，在163天的时间间隔内，我们发现平均分数漂移幅度(\vert f_{res}^{-1}df_{res}/dt\vert\lt1.4×10^{-20}/s)。谐振器频率由物理长度和光速决定，我们相对于原子时间单位对其进行测量。因此，该限制首先排除了宇宙膨胀对尺子和原子钟的假设性微分效应。我们还对基于谐振器的时钟的局部位置不变性原理的假设性违反进行了限制，并得出了时空波动强度的界限。
