Related papers: Validating a lutetium frequency reference
As optical clocks are improved to reach the frequency uncertainty below the 10$^{-17}$ level, the frequency shift due to the blackbody radiation (BBR) has been one of the major systematic effects hindering further improvement. To evaluate…
The comparison of optical reference frequency signals over free-space optical links is limited by the relative motion between local and remote sites. For ground to low earth orbit comparison, the expected Doppler shift and Doppler rate…
The Heisenberg time-energy relation prevents determination of an atomic transition to better than the inverse of the measurement time. The relation generally applies to frequency estimation of a near-resonant field [1-3], since information…
Many-particle optical lattice clocks have the potential for unprecedented measurement precision and stability due to their low quantum projection noise. However, this potential has so far never been realized because clock stability has been…
We present the first characterization of the spectral properties of superradiant light emitted from the ultra-narrow, 1 mHz linewidth optical clock transition in an ensemble of cold $^{87}$Sr atoms. Such a light source has been proposed as…
The roundoff errors in computer simulations of continuous dynamical systems, caused by finiteness of machine arithmetic, can lead to qualitative discrepancies between phase portraits of the resulting spatially discretized systems and the…
We present improved theoretical calculations of transition frequencies for the fundamental transitions $(L\!=\!0,v\!=\!1)\to(L'\!=\!0,v'\!=\!0)$ in the hydrogen molecular ions H$_2^+$ and HD$^+$ with a relative uncertainty $4\cdot10^{-11}$…
It has been found that the quantum-to-classical transition can be observed independent of macroscopicity of the quantum state for a fixed degree of fuzziness in the coarsened references of measurements. Here, a general situation, that is…
A fundamental limit to the stability of a single-ion optical frequency standard is set by quantum noise in the measurement of the internal state of the ion. We discuss how the interrogation sequence and the processing of the atomic…
We determine the frequency of the ultranarrow $^{87}\text{Sr}$ ${^{1}\text{S}_{0}} - {^{3}\text{P}_{2}}$ transition by spectroscopy of an ultracold gas. This transition is referenced to four molecular iodine lines that are observed by…
We report on an absolute frequency measurement of the ${\rm Lu}^{+}\,(^{3}\rm D_1)$ standard frequency which is defined as the hyperfine-average of $^{1}\rm S_0$ to $^{3}\rm D_1$ optical clock transitions in $^{176}{\rm Lu}^{+}$. The…
This work is devoted to quantifying how periodic perturbation can change the rate of metastable transition in stochastic mechanical systems with weak noises. A closed-form explicit expression for approximating the rate change is provided,…
We develop a simple technique to accurately measure frequency differences between far lying resonances in a spectroscopy signal using a single laser. This technique was used to measure the isotope shift of the cooling transition of…
Radio resource management in cellular networks is typically based on device measurements reported to the serving base station. Frequent measuring of signal quality on available frequencies would allow for highly reliable networks and…
Optical lattice clocks with uncertainty and instability in the $10^{-17}$-range and below have so far been demonstrated exclusively using fermions. Here, we demonstrate a bosonic optical lattice clock with $3\times 10^{-18}$ instability and…
Over a two-year duration, we have compared the frequency of the 199Hg+ 5d106s 2S 1/2 (F=0)<-> 5d9 6s2 2D 5/2 (F=2) electric-quadrupole transition at 282 nm with the frequency of the ground-state hyperfine splitting in neutral 133Cs. These…
In neutral atom optical clocks, the higher-order atomic polarizability terms lead to the clock transition frequency shift which is motion-state dependent and nonlinear with the optical lattice depth. We propose to use an auxiliary optical…
Molecular lattice clocks enable the search for new physics, such as fifth forces or temporal variations of fundamental constants, in a manner complementary to atomic clocks. Blackbody radiation (BBR) is a major contributor to the systematic…
We have constructed an optical clock with a fractional frequency inaccuracy of 8.6e-18, based on quantum logic spectroscopy of an Al+ ion. A simultaneously trapped Mg+ ion serves to sympathetically laser-cool the Al+ ion and detect its…
Predictability of flow is examined in a barotropic vorticity model that admits low frequency regime transitions between zonal and dipolar states. Such transitions in the model were first studied by Bouchet and Simonnet (2009) and are…