Wolf Fabian, Shi Chunyan, Heip Jan C, Gessner Manuel, Pezzè Luca, Smerzi Augusto, Schulte Marius, Hammerer Klemens, Schmidt Piet O
Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116, Braunschweig, Germany.
QSTAR, INO-CNR and LENS, Largo Enrico Fermi 2, I-50125, Firenze, Italy.
Nat Commun. 2019 Jul 2;10(1):2929. doi: 10.1038/s41467-019-10576-4.
The quantum noise of the vacuum limits the achievable sensitivity of quantum sensors. In non-classical measurement schemes the noise can be reduced to overcome this limitation. However, schemes based on squeezed or Schrödinger cat states require alignment of the relative phase between the measured interaction and the non-classical quantum state. Here we present two measurement schemes on a trapped ion prepared in a motional Fock state for displacement and frequency metrology that are insensitive to this phase. The achieved statistical uncertainty is below the standard quantum limit set by quantum vacuum fluctuations, enabling applications in spectroscopy and mass measurements.
真空的量子噪声限制了量子传感器可达到的灵敏度。在非经典测量方案中，可以降低噪声以克服这一限制。然而，基于压缩态或薛定谔猫态的方案需要对准测量相互作用与非经典量子态之间的相对相位。在此，我们展示了两种针对处于运动福克态的囚禁离子的测量方案，用于位移和频率计量，它们对该相位不敏感。所实现的统计不确定性低于由量子真空涨落设定的标准量子极限，从而能够应用于光谱学和质量测量。
