2026-05-21 九州大学
本研究で考察するトラップドイオン原子時計における、古典的、半古典的、および量子的な固有時ダイナミクスの模式図。ここでは、時計のダイナミクスと空間的な相対論効果が干渉する様子を示している。
＜関連情報＞
- https://www.kyushu-u.ac.jp/ja/researches/view/1485
- https://journals.aps.org/prl/abstract/10.1103/qhj9-pc2b
光イオン時計における固有時間の量子署名 Quantum Signatures of Proper Time in Optical Ion Clocks
Gabriel Sorci, Joshua Foo, Dietrich Leibfried, Christian Sanner, and Igor Pikovski
Physical Review Letters Published: 20 April, 2026
DOI: https://doi.org/10.1103/qhj9-pc2b
Abstract
Optical clocks based on atoms and ions probe relativistic effects with unprecedented sensitivity. They resolve time dilation due to atom motion or different positions in the gravitational potential through frequency shifts. However, all measurements of time dilation so far can be explained effectively as the result of dynamics with respect to a classical proper time parameter. Here we show that atomic clocks can probe effects where a classical description of the proper time dynamics is insufficient as superpositions of proper time emerge. We apply a Hamiltonian formalism to derive time dilation effects in harmonically trapped clock atoms and show how second-order Doppler shifts due to the vacuum energy, squeezing, and quantum corrections to the dynamics arise. We also demonstrate that time-dilation-induced entanglement between motion and clock evolution can become observable in state-of-the-art clocks when the motion of the atoms is strongly squeezed, realizing proper time interferometry. Our results show that experiments with trapped ion clocks are within reach of probing relativistic evolution of clocks for which a quantum description of proper time becomes necessary.
