Golovizin A, Fedorova E, Tregubov D, Sukachev D, Khabarova K, Sorokin V, Kolachevsky N
P.N. Lebedev Physical Institute, Leninsky prospekt 53, Moscow, 119991, Russia.
Russian Quantum Center, Business-Center "Ural", 100A Novaya St., Skolkovo, Moscow, 143025, Russia.
Nat Commun. 2019 Apr 12;10(1):1724. doi: 10.1038/s41467-019-09706-9.
One of the key systematic effects limiting the performance of state-of-the-art optical clocks is the blackbody radiation (BBR) shift. Here, we demonstrate unusually low sensitivity of a 1.14 μm inner-shell clock transition in neutral Tm atoms to BBR. By direct polarizability measurements, we infer a differential polarizability of the clock levels of -0.063(30) atomic units corresponding to a fractional frequency BBR shift of only 2.3(1.1) × 10 at room temperature. This amount is several orders of magnitude smaller than that of the best optical clocks using neutral atoms (Sr, Yb, Hg) and is competitive with that of ion optical clocks (Al, Lu). Our results allow the development of lanthanide-based optical clocks with a relative uncertainty at the 10 level.
限制当前最先进光学时钟性能的关键系统效应之一是黑体辐射（BBR）频移。在此，我们展示了中性铥（Tm）原子中1.14μm内壳层时钟跃迁对BBR异常低的灵敏度。通过直接极化率测量，我们推断出时钟能级的微分极化率为-0.063(30)原子单位，对应室温下仅2.3(1.1)×10的分数频率BBR频移。该数值比使用中性原子（锶（Sr）、镱（Yb）、汞（Hg））的最佳光学时钟小几个数量级，并且与离子光学时钟（铝（Al）、镥（Lu））相当。我们的结果有助于开发相对不确定度在10水平的镧系元素基光学时钟。
