Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · 0704.1974

Agile low phase noise radio-frequency sine wave generator applied to experiments on ultracold atoms

Olivier Morizot·Julien De Lapeyre De Bellair·Fabrice Wiotte·Olivier Lopez·Paul-Eric Pottie·Hélène Perrin
View original source ↗Read source document ↗Export metadata ↓

Abstract

We report on the frequency performance of a low cost (~500$) radio-frequency sine wave generator, using direct digital synthesis (DDS) and a field-programmable gate array (FPGA). The output frequency of the device may be changed dynamically to any arbitrary value ranging from DC to 10 MHz without any phase slip. Sampling effects are substantially reduced by a high sample rate, up to 1 MHz, and by a large memory length, more than 2.10^5 samples. By using a low noise external oscillator to clock the DDS, we demonstrate a phase noise as low as that of the master clock, that is at the level of -113 dB.rad^2/Hz at 1 Hz from the carrier for an output frequency of 3.75 MHz. The device is successfully used to confine an ultracold atomic cloud of rubidium 87 in a RF-based trap, and there is no extra heating from the RF source.

Explore related subjects

physics.atom-ph

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Olivier Morizot, Julien De Lapeyre De Bellair, Fabrice Wiotte, Olivier Lopez, Paul-Eric Pottie, Hélène Perrin. 2007-04-16. Agile low phase noise radio-frequency sine wave generator applied to experiments on ultracold atoms. https://arxiv.org/abs/0704.1974

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Momentum-space signatures of radial orbital nodes in XUV photoionization

Photoelectron momentum distributions (PMDs) are widely used to probe light matter interactions, yet their angular features are generally assumed to be governed primarily by angular momentum selection rules. We show that the radial structure of the initial bound orbital can qualitatively modify PMD tilt beyond these con- ventional expectations. Using ab-initio time dependent Schrödinger equation calculations, we demonstrate this through comparative studies of single-photon XUV ionization in neon and argon. While neon exhibits a smooth, monotonic increase in PMD tilt with wavelength, argon shows pronounced suppression and reversal near the wavelength where the d wave dipole matrix element passes through a minimum. A partial wave analysis reveals that this non monotonic behaviour originates from a radial node induced minimum in the d wave dipole matrix element, producing a rapid phase jump between interfering s and d wave ionization channels. We further show that atomic interferometric circular dichroism (AICD) provides a sensitive, experimentally accessible probe of this effect.

physics.atom-ph↗
arXiv2026

Extreme-ultraviolet spectroscopy using quantum logic: a feasibility study for the 1S-2S transition in singly-ionized helium

Extreme-ultraviolet (XUV) spectroscopy represents an important new direction in precision physics, with potential applications ranging from the metrology of fundamental constants to tests of physics beyond the Standard Model. However, the application of quantum control methods for precision spectroscopy remains an open challenge in the XUV range. Here we present a novel quantum logic (QL) spectroscopy method for precision spectroscopy of weak XUV transitions, and numerically validate its feasibility for the $1S-2S$ transition at 40.81\,eV in singly-ionized helium (He$^{+}$). We propose a scheme based on a single He$^{+}$ ion co-trapped with a Be$^{+}$ ion in a Paul trap, and He$^{+}$ excitation with pairs of frequency-comb (FC) laser pulses upconverted to the XUV via High-Harmonic Generation (HHG). We investigate a nondestructive QL scheme to detect $1S-2S$ excitation, and compare its performance with a destructive readout based on state-selective ionization. Phase coherence of the XUV light is modelled and an optical cavity is used to filter the FC pulses prior to HHG. We model the motional excitation dynamics of trapped ions outside the Lamb-Dicke regime, and numerically validate a scheme we proposed in \cite{Grundeman} to cancel the first-order Doppler broadening and the recoil shift by synchronizing the ion's secular period with the time delay between the two excitation pulses. We show that precision spectroscopy of the $1S-2S$ transition in He$^{+}$ at the 10 kHz level is feasible, for improved tests of quantum electrodynamics (QED), a measurement of the Rydberg constant $R_{\infty}$ independent of hydrogen measurements, or an improved determination of the alpha particle and helion charge radii. The proposed method may also be applied to XUV spectroscopy of other ions outside the Lamb-Dicke regime.

physics.atom-ph↗
arXiv2026

Second-Order Rayleigh-Schrödinger Perturbation Theory for the Grasp

A developed method, based on the stationary second-order Rayleigh-Schrödinger many-body perturbation theory in an irreducible tensorial form, allows us to determine the most important core-valence, core, core-core, and valence-valence correlations for any atom or ion with an arbitrary number of valence and core electrons. This paper presents the Feynman diagrams that describe these correlations. Additionally, it provides the rules for obtaining algebraic expressions in an irreducible tensorial form for any Feynman diagram coming from second-order many-body perturbation theory. Whereas some types of the valence-valence and core-valence correlations are described by the three-particle Feynman diagrams, additional developments to calculate the spin-angular parts of these diagrams have been made to the program library librang of the Grasp2018. As an example of the application of the developed method, the atomic calculations of the energy level structure and transition data for Ar II are presented.

physics.atom-ph↗