Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Journal of Applied Physics

Ultrahigh vacuum pressure measurement using magneto-optical trap on atom chip

S. Supakar, Vivek Singh, Vibhuti Bhushan Tiwari, Satya Ram Mishra

Published Jul 10, 2023• 6 citations
Publisher

Abstract

In this work, the UHV background pressure as low as 1.1×10−10 Torr has been measured using the loss rate characteristics of a vapor-loaded magneto-optical trap (MOT) formed on an atom chip in a UHV chamber. The loss rate due to non-rubidium (Rb) gases in the background in the chamber has been estimated by operating the MOT in low cooling beam intensities and low Rb pressure regimes simultaneously. Using this approach, we minimized the contributions of the intra-trap collisions as well as background MOT species collisions to the measured trap loss rate in our setup. These results can be useful for development of cold-atom based UHV pressure standards.

DOI
10.1063/5.0156305

Related papers

Ultra-high vacuum pressure measurement using cold atoms

S. Supakar, Vivek Singh, Tiwari, V. B. +1 more

In this work, we have measured the background pressure in an ultra-high vacuum (UHV) chamber by measuring the collisional loss rates in a Rb atom magneto-optical trap (MOT) on an atom chip. The loss rate due to non-Rb gases in the background has been estimated by measuring the MOT loss rate in low Rb pressure regime. These results can be useful for development of cold-atoms based UHV pressure standards.

arXiv:2302.14305•Feb 28, 2023•0 citations

Pulsed loading of a magneto-optical trap on atom chip for fast pressure recovery in ultrahigh vacuum environment

Singh, Vivek, Vibhuti Bhushan Tiwari, A. Chaudhary +2 more

This study presents investigations on pulsed loading of a magneto-optical trap (MOT) on an atom chip in an UHV environment. Using three parallel resistively heated Rb-metal dispensers activated by pulsed current supply, approximately 3.0 $\times$ $10^{7}$ cold $^{87}Rb$ atoms were loaded into the MOT. A current pulse of $\sim$ 24 A with duration of $\sim$ 10 s raised the pressure in the chamber from 2.0 $\times$ $10^{-10}$ Torr to 3.3 $\times$ $10^{-10}$ Torr. Remarkably, the pressure recovery time after switching off the dispensers current was found to be $\sim$ 600 ms, making a significant advancement in achieving fast recovery of UHV environment surrounding the MOT region. This study is very useful for laser cooling and magnetic trapping / evaporative cooling of atoms on atom chip in the same UHV chamber.

arXiv:2403.11458•Mar 18, 2024•0 citations

On the continuous loading of a U-magneto-optical trap on an atom-chip in an ultra high vacuum

Vivek Singh, Vibhuti Bhushan Tiwari, Satya Ram Mishra

Abstract Here, we report our studies on the continuous loading of a U-magneto-optical trap (U-MOT) on an atom-chip with a rubidium-(Rb)-vapor-generated background using a dispenser source in an ultra high vacuum environment. Using the U-MOT loading curves, the partial pressure due to the Rb vapor and the pressure due to the background gas have been estimated near the MOT cloud position. The estimated pressure due to the Rb vapor increased from ∼ Torr to Torr as the Rb-dispenser current was increased from 2.8 to 3.4 A. The increase in dispenser current also resulted in a decrease in loading time as well as the lifetime of the MOT cloud. This study will be useful for magnetic trapping experiments where accurate information of the pressure in a chamber is important for the lifetime of the magnetic trap.

arXiv:1912.07934•Laser Physics Letters•Jan 28, 2020•11 citations

Pulsed loading of a magneto-optical trap on an atom chip with fast recovery of ultrahigh vacuum

Vivek Singh, Vibhuti Bhushan Tiwari, A Chaudhary +2 more

Abstract Here, we present studies on pulsed loading of a rubidium (Rb) magneto-optical trap (MOT) in an ultra-high vacuum (UHV) environment on an atom chip. We have used a parallel combination of Rb dispensers for better heat dissipation to achieve fast UHV recovery in the chamber after the end of the current pulse to the dispensers. We have estimated the threshold heat energy required for activation of the dispensers for different values of current pulses. Although a pulse with a higher current value and shorter duration has a lower threshold heat energy, we operated the dispensers at moderate current pulse parameters (24 A, 10 s) for protection of the circuits. Nearly, 3 × 10 7 cold 87 Rb atoms were loaded in the MOT using this current pulse, with a UHV recovery time of ∼600 ms in the chamber. This fast recovery of UHV in the MOT chamber is useful for further experiments such as magnetic trapping and evaporative cooling of atoms in the same chamber.

Laser Physics Letters•Dec 19, 2024•0 citations

Vacuum pressure measurement based on 6Li cold atoms in a magneto-optical trap

Suzhao Zhang, Wenjun Sun, Meng Dong +5 more

Ultra-high vacuum measurement and extremely high vacuum (UHV/XHV) measurement play an important role in high-tech fields such as deep space exploration, particle accelerators, and nanoscience; with the continuous extension of the lower limit of measurement, especially when it reaches the order of 10–10 Pa, higher requirements are placed on the accuracy of the measurement. At present, in the field of UHV/XHV measurement, ionization gauges based on the principle of neutral gas ionization are commonly applied to the vacuum measurement. However, traditional ionization vacuum gauges during use can create electronic excitation desorption effects, soft X-rays, and the effect of hot cathode outgassing, thereby affecting the accuracy of measurement and limiting the lower limit of measurement. Compared with the traditional measurement technology, this method uses the relationship between the loss rate and pressure caused by the collision of cold atoms trapped in the trap depth with the background gas to calculate the gas density and inversely calculate the vacuum pressure. Based on the intrinsic quantum mechanical properties of cold atom collisions, this method is expected to be developed into a new vacuum traceability standard. In this paper, based on the small-angle approximation and impulse approximation under the quantum scattering theory, the loss rate coefficient of the collision of 6Li cold atoms with background gas molecules is calculated. According to the ideal gas equation, the pressure inversion formula is obtained. The collision loss rate is extracted by accurately fitting the loss curve of the cold atom. In order to improve the accuracy of vacuum inversion and reduce the influence of quantum diffractive collision on loss rate measurement, the trap depth under the conditions of a certain cooling laser intensity, detuning, and magnetic field gradient is determined by the photoassociation method. Finally, in a range of 1 × 10–8–5 × 10–6 Pa, the inverted pressure value is compared with the measured value of the ionization meter, proving that this method has good accuracy and reliability in the inversion of vacuum pressure. At present, the main factor restricting the improvement of accuracy is the influence of the collision between the excited atoms in the magneto-optical trap and the background gas on the loss rate measurement. In the future, with the proportion of excited atoms and the excited state C6 coefficient to be precisely determined, the uncertainty of vacuum pressure measurement can be further reduced.

Acta Physica Sinica•Jan 1, 2022•4 citations

A compact setup for loading magneto-optical trap in ultrahigh vacuum environment

Kavish Bharadwaj, Sourabh Sarkar, S. P. Ram +2 more

We have developed a compact setup which enables loading a magneto-optical trap (MOT) in ultra-high vacuum (UHV) environment. Nearly $1 \times 10^{8}$ atoms of $^{87}Rb$ are trapped in the MOT at $\sim 2 \times 10^{-10}$ Torr base pressure in the chamber. After the MOT loading, we have successfully demonstrated working of quadrupole magnetic trap in this chamber with a lifetime of $\sim 8 $ s

arXiv:2206.13271•Jun 27, 2022•0 citations
In this work, the UHV background pressure as low as 1.1×10−10 Torr has been measured using the loss rate characteristics of a vapor-loaded magneto-optical trap (MOT) formed on an atom chip in a UHV chamber. The loss rate due to non-rubidium (Rb) gases in the background in the chamber has been estimated by operating the MOT in low cooling beam intensities and low Rb pressure regimes simultaneously. Using this approach, we minimized the contributions of the intra-trap collisions as well as background MOT species collisions to the measured trap loss rate in our setup. These results can be useful for development of cold-atom based UHV pressure standards.
This study presents investigations on pulsed loading of a magneto-optical trap (MOT) on an atom chip in an UHV environment. Using three parallel resistively heated Rb-metal dispensers activated by pulsed current supply, approximately 3.0 ×\times× 10710^{7}107 cold 87Rb^{87}Rb87Rb atoms were loaded into the MOT. A current pulse of ∼\sim∼ 24 A with duration of ∼\sim∼ 10 s raised the pressure in the chamber from 2.0 ×\times× 10−1010^{-10}10−10 Torr to 3.3 ×\times× 10−1010^{-10}10−10 Torr. Remarkably, the pressure recovery time after switching off the dispensers current was found to be ∼\sim∼ 600 ms, making a significant advancement in achieving fast recovery of UHV environment surrounding the MOT region. This study is very useful for laser cooling and magnetic trapping / evaporative cooling of atoms on atom chip in the same UHV chamber.
Abstract Here, we report our studies on the continuous loading of a U-magneto-optical trap (U-MOT) on an atom-chip with a rubidium-(Rb)-vapor-generated background using a dispenser source in an ultra high vacuum environment. Using the U-MOT loading curves, the partial pressure due to the Rb vapor and the pressure due to the background gas have been estimated near the MOT cloud position. The estimated pressure due to the Rb vapor increased from ∼ Torr to Torr as the Rb-dispenser current was increased from 2.8 to 3.4 A. The increase in dispenser current also resulted in a decrease in loading time as well as the lifetime of the MOT cloud. This study will be useful for magnetic trapping experiments where accurate information of the pressure in a chamber is important for the lifetime of the magnetic trap.
Abstract Here, we present studies on pulsed loading of a rubidium (Rb) magneto-optical trap (MOT) in an ultra-high vacuum (UHV) environment on an atom chip. We have used a parallel combination of Rb dispensers for better heat dissipation to achieve fast UHV recovery in the chamber after the end of the current pulse to the dispensers. We have estimated the threshold heat energy required for activation of the dispensers for different values of current pulses. Although a pulse with a higher current value and shorter duration has a lower threshold heat energy, we operated the dispensers at moderate current pulse parameters (24 A, 10 s) for protection of the circuits. Nearly, 3 × 10 7 cold 87 Rb atoms were loaded in the MOT using this current pulse, with a UHV recovery time of ∼600 ms in the chamber. This fast recovery of UHV in the MOT chamber is useful for further experiments such as magnetic trapping and evaporative cooling of atoms in the same chamber.
Ultra-high vacuum measurement and extremely high vacuum (UHV/XHV) measurement play an important role in high-tech fields such as deep space exploration, particle accelerators, and nanoscience; with the continuous extension of the lower limit of measurement, especially when it reaches the order of 10–10 Pa, higher requirements are placed on the accuracy of the measurement. At present, in the field of UHV/XHV measurement, ionization gauges based on the principle of neutral gas ionization are commonly applied to the vacuum measurement. However, traditional ionization vacuum gauges during use can create electronic excitation desorption effects, soft X-rays, and the effect of hot cathode outgassing, thereby affecting the accuracy of measurement and limiting the lower limit of measurement. Compared with the traditional measurement technology, this method uses the relationship between the loss rate and pressure caused by the collision of cold atoms trapped in the trap depth with the background gas to calculate the gas density and inversely calculate the vacuum pressure. Based on the intrinsic quantum mechanical properties of cold atom collisions, this method is expected to be developed into a new vacuum traceability standard. In this paper, based on the small-angle approximation and impulse approximation under the quantum scattering theory, the loss rate coefficient of the collision of 6Li cold atoms with background gas molecules is calculated. According to the ideal gas equation, the pressure inversion formula is obtained. The collision loss rate is extracted by accurately fitting the loss curve of the cold atom. In order to improve the accuracy of vacuum inversion and reduce the influence of quantum diffractive collision on loss rate measurement, the trap depth under the conditions of a certain cooling laser intensity, detuning, and magnetic field gradient is determined by the photoassociation method. Finally, in a range of 1 × 10–8–5 × 10–6 Pa, the inverted pressure value is compared with the measured value of the ionization meter, proving that this method has good accuracy and reliability in the inversion of vacuum pressure. At present, the main factor restricting the improvement of accuracy is the influence of the collision between the excited atoms in the magneto-optical trap and the background gas on the loss rate measurement. In the future, with the proportion of excited atoms and the excited state C6 coefficient to be precisely determined, the uncertainty of vacuum pressure measurement can be further reduced.
We have developed a compact setup which enables loading a magneto-optical trap (MOT) in ultra-high vacuum (UHV) environment. Nearly 1×1081 \times 10^{8}1×108 atoms of 87Rb^{87}Rb87Rb are trapped in the MOT at ∼2×10−10\sim 2 \times 10^{-10}∼2×10−10 Torr base pressure in the chamber. After the MOT loading, we have successfully demonstrated working of quadrupole magnetic trap in this chamber with a lifetime of $\sim 8 $ s