arXiv subjects

Thomas Lauprêtre

Publications and source records attributed to Thomas Lauprêtre.

8 recordsLinked to original sources

arXiv2025

First observation and measurement of the ${}^{198}\text{Hg}$ bosonic transition in an optical lattice clock

We report the first observation of the magnetic-field-induced (5d10 6s2)1S0-(5d10 6s6p)3P0 transition in a bosonic isotope of mercury, 198Hg, realized in an optical lattice clock. We characterize this new isotope, determining key features such as the quadratic Zeeman shift, the probe light shift, and the magic frequency. We also report a first comparison between the 198Hg optical lattice clock and 87Sr. In this comparison, the 198Hg clock has a relative frequency stability of 6x10-16/sqrt(tau/s) and a total relative systematic uncertainty of 6.9x10-16. This comparison yields the first direct determination of the 198Hg/87Sr optical frequency ratio: 198Hg/87Sr = 2.629 315 734 684 118 1, with the same relative uncertainty.

physics.atom-ph↗

arXiv2025

Probing Coherences and Itinerant Magnetism in a Dipolar Lattice Gas

We report on the study of itinerant magnetism of lattice-trapped magnetic atoms, driven by magnetic dipole-dipole interactions, in the low-entropy and close-to-unit filling regime. We have used advanced dynamical decoupling techniques to efficiently suppress the sensitivity to magnetic field fluctuations. We have thus measured the spin coherence of an itinerant spin 3 Bose dipolar gas throughout a quantum phase transition from a superfluid phase to a Mott insulating phase. In the superfluid phase, a metastable ferromagnetic behavior is observed below a dynamical instability which occurs at lattice depths below the phase transition. In the insulating phase, the thermalization towards a paramagnetic state is driven by an interplay between intersite and superexchange interactions.

cond-mat.quant-gas↗

arXiv2024

Preliminary characterization of a surface electrode Paul trap for frequency metrology

We are developing a single-ion optical clock based on a surface-electrode (SE) trap that we will operate with $^{171}$Yb$^+$ ions on the electric quadrupole transition at 435.5 nm. We present heating rate measurements performed with a prototype SE trap. We also introduce a new, micro-fabricated SE trapping chip using silicon on insulator technology. Electric tests were performed under ultra-high vacuum using a testing chip, including breakdown voltages measurements and flashover detection. We present suitable trapping parameters for this chip, as well as a road-map for improving its design.

physics.atom-ph↗

arXiv2022

Heating rate measurement and characterization of a prototype surface-electrode trap for optical frequency metrology

We present the characterization of a prototype surface-electrode (SE) trap as a first step towards the realization of a compact, single-ion optical clock based on Yb$^+$. The use of a SE trap will be a key factor to benefit from clean-room fabrication techniques and technological advances made in the field of quantum information processing. We succesfully demonstrated trapping at a 500 $μ$m electrodes distance and characterized our trap in terms of lifetime and heating rate. This is to our knowledge the highest distance achieved for heating rates measurements in SE traps. This simple 5-wire design realized with simple materials yields a heating rate of $\mathbf{8\times 10^3}$ phonons/s. We provide an analysis of the performances of this prototype trap for optical frequency metrology.

quant-ph↗

arXiv2019

Absolute frequency measurements of the ${}^1{\rm S}_0 \rightarrow {}^1{\rm P}_1$ transition in ytterbium

The ytterbium atom is widely used in the fields of atomic physics, cavity quantum electrodynamics, quantum information processing and optical frequency standards. There is however a strong dispersion among the reported values of the ${}^1{\rm S}_0 \rightarrow {}^1{\rm P}_1$ transition frequency. In this article, we present two independent measurements of the absolute frequency of this transition performed with two different wavemeters using atomic fluorescence spectroscopy. The cancellation of Doppler shifts is obtained by fine tuning the angle between the probe laser and the atomic beam. The resulting $^{174}\mathrm{Yb}$ isotope transition frequency is estimated to be $\,751\,526\,537\pm27$ MHz.

physics.atom-ph↗

arXiv2019

Controlling the potential landscape and normal modes of ion Coulomb crystals by a standing wave optical potential

Light-induced control of ions within small Coulomb crystals is investigated. By intense intracavity optical standing wave fields, subwavelength localization of individual ions is achieved for one-, two-, and three-dimensional crystals. Based on these findings, we illustrate numerically how the application of such optical potentials can be used to tailor the normal mode spectra and patterns of multi-dimensional Coulomb crystals. The results represent, among others, important steps towards controlling the crystalline structure of Coulomb crystals, investigating heat transfer processes at the quantum limit and quantum simulations of many-body systems.

quant-ph↗

arXiv2017

Localization of ions within one-, two- and three-dimensional Coulomb crystals by a standing wave optical potential

We demonstrate light-induced localization of Coulomb-interacting particles in multi-dimensional structures. Subwavelength localization of ions within small multi-dimensional Coulomb crystals by an intracavity optical standing wave field is evidenced by measuring the difference in scattering inside symmetrically red- and blue-detuned optical lattices and is observed even for ions undergoing substantial radial micromotion. These results are promising steps towards the structural control of ion Coulomb crystals by optical fields as well as for complex many-body simulations with ion crystals or for the investigation of heat transfer at the nanoscale, and have potential applications for ion-based cavity quantum electrodynamics, cavity optomechanics and ultracold ion chemistry.

quant-ph↗

arXiv2011

Photon lifetime in a cavity containing a slow-light medium

We investigate experimentally the lifetime of the photons in a cavity containing a medium exhibiting strong positive dispersion. This intracavity positive dispersion is provided by a metastable helium gas at room temperature in the electromagnetically induced transparency (EIT) regime, in which light propagates at a group velocity of the order of 10000 m/s. The results definitely prove that the lifetime of the cavity photons is governed by the group velocity of light in the cavity, and not its phase velocity.

physics.optics↗