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.
We have developed a compact vacuum system for laser cooling and spectroscopy of neutral thulium atoms. Compactness is achieved by obviating a classical Zeeman slower section and placing an atomic ...oven close to a magneto-optical trap (MOT), specifically at the distance of 11 cm. In this configuration, we significantly gained in solid angle of an atomic beam, which is affected by MOT laser beams, and reached 1 million atoms loaded directly in the MOT with only 15 mW of MOT cooling beams net power. By exploiting Zeeman-like deceleration of atoms with an additional laser beam and tailoring the MOT magnetic field gradient with a small magnetic coil, we demonstrated trapping of up to 13 million atoms. These results show great perspective of the developed setup for realizing a compact high-performance optical atomic clock based on thulium atoms.
Abstract
Optical atomic clocks have already overcome the eighteenth decimal digit of instability and uncertainty, demonstrating incredible control over external perturbations of the clock transition ...frequency. At the same time, there is an increasing demand for atomic (ionic) transitions and new interrogation and readout protocols providing minimal sensitivity to external fields and possessing practical operational wavelengths. One of the goals is to simplify the clock operation while maintaining the relative uncertainty at a low 10
−18
level achieved at the shortest averaging time. This is especially important for transportable and envisioned space-based optical clocks. Here, we demonstrate implementation of a synthetic frequency approach for a thulium optical clock with simultaneous optical interrogation of two clock transitions. Our experiment shows suppression of the quadratic Zeeman shift by at least three orders of magnitude. The effect of the tensor lattice Stark shift in thulium can also be reduced to below 10
−18
in fractional frequency units. This makes the thulium optical clock almost free from hard-to-control systematic shifts. The “simultaneous” protocol demonstrates very low sensitivity to the cross-talks between individual clock transitions during interrogation and readout.
The experimental comparison of two thulium optical lattice clocks in a time interval of up to one hour has been carried out. The synchronous comparison of a clock transition in two independent atomic ...ensembles using a single ultrastable laser has allowed us to eliminate fluctuations of the laser frequency from the measured frequency difference and to reach a relative measurement error of 10
–16
after 500-s averaging, which corresponds to a relative instability of
. The successful demonstration of the long-term operation of two systems using the synchronous comparison of clock transitions opens the possibility of studying systematic shifts in thulium optical clocks with an uncertainty of 10
–17
.
The unprecedented flux of low energy antiprotons delivered by the Extra Low ENergy Antiprotons (ELENA) ring, being under commissioning at CERN, will open a new era for precision tests with antimatter ...including laser and microwave spectroscopy and tests ofits gravitational behaviour. Here we present an alternative to magnetic trapping to perform ultra-high precision laser spectroscopy of antihydrogen. The proposed scheme is to load the ultra cold anti-hydrogen atoms produced by the GBAR experiment in an optical trap tuned at the magicwavelength of the 1S–2S transition in order to measure this interval at a level comparable or even better than its matter counter part. This will provide a very accurate test of Lorentz/CPT violating effects which can be parametrised in the framework of the Standard Model Extension.
A method for the joint application of two coupled quantum memristors on a single
171
Yb
+
ion by using optical and radio-frequency transitions induced by resonant laser fields is proposed. As a ...result, coherent mapping of the input quantum state to the output state is created. The proposed method makes it possible to use only one ion to control statistical weights in two-layer perceptrons.
In the paper, we describe a method for searching for the optimal parameters of laser cooling of strontium ions without observing the luminescence signal. The presented method made it possible to ...obtain a cold cloud of ions, detect the luminescence signal, and achieve the mode of ionic crystals.
Crystalline neon film was condensed on a gold surface and reflected electron energy-loss spectra (REELS) was measured at the temperature of 5 K. Also face-centered-cubic (FCC) Ne was investigated ...theoretically using density-functional theory (DFT), GW approximation, random-phase approximation (RPA) and the Bethe–Salpeter equation (BSE). REELS was calculated in the independent particles level, and including many-body perturbation effects – appearance of the electron-hole pairs (e–h), local-field dielectric screening and excitons. Calculated electronic bandgap is 21.5 eV. Analyzing obtained theoretical and experimental REELS we conclude that first excitonic peak appears at 17.8 eV and all the peaks up to 21.5 eV are purely excitonic. Solid neon film, being a wide-gap dielectric, considered as promising material for implanting Th and studying its low-lying nuclear transition at 8.2 eV.
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