© 2026 Aqora Quantum S.A.S.

Terms Privacy Legal Notice

Journal of the Physical Society of Japan

Measurement of the Spatial Distribution of Ultracold Cesium Rydberg Atoms by Time-of-Flight Spectroscopy

Jingkui Li, Linjie Zhang, Hao Zhang, Jianming Zhao, Suotang Jia

Published Sep 1, 2015• 0 citations

Abstract

We prepare nS (n = 49) cesium Rydberg atoms by two-photon excitation in a standard magnetooptical trap to obtain the spatial distribution of the Rydberg atoms by measuring the time-of-flight (TOF) spectra in the case of a low Rydberg density. We analyze the time evolution of the ultracold nS Rydberg atoms distribution by changing the delay time of the pulsed ionization field, defined as the duration from the moment of switching off the excitation lasers to the time of switching on the ionization field. TOF spectra of Rydberg atoms are observed as a function of the delay time and initial Rydberg atomic density. The corresponding full widths at half maximum (FWHMs) are obtained by fitting the spectra with a Gaussian profile. The FWHM decreases with increasing delay time at a relatively high Rydberg atom density (>5 × 107/cm3) because of the decreasing Coulomb interaction between released charges during their flight to the detector. The temperature of the cold atoms is deduced from the dependence of the TOF spectra on the delay time under the condition of low Rydberg atom density.

DOI: 10.7566/jpsj.84.094301

Related papers

Measurement of lifetime of ultracold cesium Rydberg states

Zhigang Feng, Hao Zhang, Linjie Zhang +3 more

In this paper, the cold cesium atoms are excited to Rydberg states via two-photon transition and the ion signal of Rydberg atoms is obtained by the selective field-ionization method. The evolution of the 36D and 34S states population is acquired by changing delay time; the corresponding effective lifetimes are obtained by fitting the experimental data, which are in agreement with the existing theoretical results.

Acta Physica Sinica•Jan 1, 2011•4 citations

Measurement of quantum defects ofnS andnD states using field ionization spectroscopy in ultracold cesium atoms

Linjie Zhang, Zhigang Feng, LI An-Ling +3 more

This paper reports that ultracold atoms are populated into different nS and nD Rydberg states (n = 25~52) by two-photon excitation. The ionization spectrum of an ultracold Rydberg atom is acquired in a cesium magneto-optical trap by using the method of pulse field ionization. This denotes nS and nD states in the ionization spectrum and fits the data of energy levels of different Rydberg states to obtain quantum defects of nS and nD states.

Chinese Physics B•May 1, 2009•6 citations

Excitation Dynamics of Ultracold Cesium nS Rydberg Atoms

Hao Zhang, Junling Che, Zhigang Feng +3 more

Ultracold cesium n S ( n =60–70) Rydberg atoms are prepared using the two-photon scheme in a magneto-optical trap (MOT). The number of resonant Rydberg atoms is measured by the pulsed field ionization technique, and the dependences of the Rydberg signal on excitation duration and external DC electric field are investigated. The excitation dynamics and blockade effects due to long-range interactions are obtained. The effect of external electric field on Rydberg excitation is also investigated, and the experimental result shows an enhanced blockade with a weak external electric field.

Journal of the Physical Society of Japan•Sep 22, 2011•2 citations

Recombination during expansion of ultracold plasma

Jianming Zhao, Linjie Zhang, Zhigang Feng +2 more

Signals of ultracold plasma are observed by two-photon ionization of laser-cooled caesium atoms in a magneto-optical trap. Recombination of ions and electrons into Rydberg atoms during the expansion of ultracold plasma is investigated by using state-selective field ionization spectroscopy. The dependences of recombination on initial electron temperature (1–70 K) and initial ion density (∼10 10 cm −3 ) are investigated. The measured dependence on initial ion density is N 1.547+0.004 at a delay time of 5 μs. The recombination rate rapidly declines as initial electron temperature increases when delay time is increased. The distributions of Rydberg atoms on different values of principal quantum number n, i.e. n = 30–60, at an initial electron temperature of 3.3 K are also investigated. The main experimental results are approximately explained by the three-body recombination theory.

Chinese Physics B•Apr 1, 2010•7 citations

Evolution of ultracold 70S Cs Rydberg atom

Che Jun-Ling, Hao Zhang, Zhigang Feng +3 more

Ultracold 70S Cs Rydberg atoms are obtained by two-photon excitation in a magneto-optical trap, and detected by using the state-selective pulse field ionization technique. The evolution of 70S Rydberg atoms is investigated by changing the delay time between excitation laser and ionization electric field and the excitation duration. Blackbody radiation is taken into account to explain experimental result. The experimental result is found to be consistent with theoretical value.

Acta Physica Sinica•Jan 1, 2012•2 citations

Emission of fast atoms from a cold Rydberg gas

Brenton Knuffman, Georg A. Raithel

Rydberg-Rydberg collisions in a cold, dense Rydberg gas can lead to the conversion of internal energy into center-of-mass energy of the colliding atoms, resulting in Rydberg-atom velocities much larger than the initial velocities in the gas. We prepare cold Rydberg-atom gases by laser excitation of laser-cooled atom clouds and use time-of-flight measurements to demonstrate the production of fast Rydberg atoms. The velocity distributions of Rydberg atoms emerging from the Rydberg-atom gases are obtained. State-selective field ionization spectra indicate a correlation between the production of fast Rydberg atoms and the presence of Penning ionization signatures. The dependence of the yield of fast Rydberg atoms on Rydberg atom density is measured.

Physical Review A•Feb 16, 2006•19 citations

We prepare nS (n = 49) cesium Rydberg atoms by two-photon excitation in a standard magnetooptical trap to obtain the spatial distribution of the Rydberg atoms by measuring the time-of-flight (TOF) spectra in the case of a low Rydberg density. We analyze the time evolution of the ultracold nS Rydberg atoms distribution by changing the delay time of the pulsed ionization field, defined as the duration from the moment of switching off the excitation lasers to the time of switching on the ionization field. TOF spectra of Rydberg atoms are observed as a function of the delay time and initial Rydberg atomic density. The corresponding full widths at half maximum (FWHMs) are obtained by fitting the spectra with a Gaussian profile. The FWHM decreases with increasing delay time at a relatively high Rydberg atom density (>5 × 107/cm3) because of the decreasing Coulomb interaction between released charges during their flight to the detector. The temperature of the cold atoms is deduced from the dependence of the TOF spectra on the delay time under the condition of low Rydberg atom density.

Ultracold cesium n S ( n =60–70) Rydberg atoms are prepared using the two-photon scheme in a magneto-optical trap (MOT). The number of resonant Rydberg atoms is measured by the pulsed field ionization technique, and the dependences of the Rydberg signal on excitation duration and external DC electric field are investigated. The excitation dynamics and blockade effects due to long-range interactions are obtained. The effect of external electric field on Rydberg excitation is also investigated, and the experimental result shows an enhanced blockade with a weak external electric field.

Signals of ultracold plasma are observed by two-photon ionization of laser-cooled caesium atoms in a magneto-optical trap. Recombination of ions and electrons into Rydberg atoms during the expansion of ultracold plasma is investigated by using state-selective field ionization spectroscopy. The dependences of recombination on initial electron temperature (1–70 K) and initial ion density (∼10 10 cm −3 ) are investigated. The measured dependence on initial ion density is N 1.547+0.004 at a delay time of 5 μs. The recombination rate rapidly declines as initial electron temperature increases when delay time is increased. The distributions of Rydberg atoms on different values of principal quantum number n, i.e. n = 30–60, at an initial electron temperature of 3.3 K are also investigated. The main experimental results are approximately explained by the three-body recombination theory.

Rydberg-Rydberg collisions in a cold, dense Rydberg gas can lead to the conversion of internal energy into center-of-mass energy of the colliding atoms, resulting in Rydberg-atom velocities much larger than the initial velocities in the gas. We prepare cold Rydberg-atom gases by laser excitation of laser-cooled atom clouds and use time-of-flight measurements to demonstrate the production of fast Rydberg atoms. The velocity distributions of Rydberg atoms emerging from the Rydberg-atom gases are obtained. State-selective field ionization spectra indicate a correlation between the production of fast Rydberg atoms and the presence of Penning ionization signatures. The dependence of the yield of fast Rydberg atoms on Rydberg atom density is measured.