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

Physical Review A

Resistive cooling of ions' center-of-mass energy in a Penning trap on millisecond time scales

Markus Kiffer, Stefan Ringleb, Th. Stöhlker, Manuel Vogel

Published Mar 4, 2024• 8 citations
Publisher

Abstract

We have performed systematic measurements of the resistive cooling behavior of bunches of highly charged ions in a Penning trap after injection from an external source. In particular, we have been able to measure the exponential cooling rate of the axial center-of-mass motion and experimentally show its linear dependence on the ion number within the bunch, as expected from theory. The common center-of-mass energy of the ions is reduced by more than four orders of magnitude on the time scale of milliseconds while the single-ion cooling occurs on the scale of seconds, representing a highly effective way to remove the dominating part of the ion kinetic energy. Published by the American Physical Society 2024

DOI
10.1103/physreva.109.033102

Related papers

Resistive cooling of highly charged ions in a Penning trap to a fluidlike state

Mehri Sadat Ebrahimi, Zhi Min Guo, Manuel Vogel +3 more

We perform a detailed experimental study of resistive cooling of large ensembles of highly charged ions such as ${\mathrm{Ar}}^{13+}$ in a cryogenic Penning trap. Different from the measurements reported by Vogel et al. [M. Vogel et al., Phys. Rev. A 90, 043412 (2014)], we observe purely exponential cooling behavior when conditions are chosen to allow collisional thermalization of the ions. We provide evidence that in this situation resistive cooling time constants and final temperatures are independent of the initial ion energy and that the cooling time constant of a thermalized ion ensemble is identical to the single-ion cooling time constant. For sufficiently high ion number densities, our measurements show discontinuities in the spectra of motional resonances which indicate a transition of the ion ensemble to a fluidlike state when cooled to temperatures below approximately 14 K. With the final ion temperature presently being 7.5 K, ions of the highest charge states are expected to form ion crystals by mere resistive cooling, in particular not requiring the use of laser cooling.

arXiv:1809.08606•Physical Review A•Aug 27, 2018•15 citations

Evaporative Cooling and Coherent Axial Oscillations of Highly Charged Ions in a Penning Trap

M. Hobein, A. Solders, M. Suhonen +2 more

Externally, in an electron beam ion trap, generated Ar16+ ions were retrapped in a Penning trap and evaporatively cooled in their axial motion. The cooling was observed by a novel extraction technique based on the excitation of a coherent axial oscillation which yields short ion bunches of well-defined energies. The initial temperature of the ion cloud was decreased by a factor of more than 140 within 1 s, while the phase-space density of the coldest extracted ion pulses was increased by a factor of up to about 9.

Physical Review Letters•Jan 7, 2011•33 citations

Experimental observations of resistive cooling of He{sup +} ions in a Penning trap

Stephen Cornford, R.A. Keneficks

A Penning trap which is optimized for transverse resistive cooling yields a cooling time constant for trapped He{sup +} ions of as low as 3 seconds, depending on cooling duty cycle. Opposite quadrants of the ring electrode resonate (Q=1800 at 7.4 MHz) with Nb/Ti inductors at 4.2 K. The f{prime} motion is resonantly cooled by operation at 2 Tesla axial field and trap voltages from 12 to 38 Volts. Ion signals are magnetically coupled to a 4 K GaAs fet preamplifier, wide-band 300 K amplifier and linear diode detection system. The rate of cooling is set by fractional time on resonance during sweep of the trap voltage. Shifting and broadening due to space charge are demonstrated. Other interesting features of the ion spectra, such as peak structure, response to heating by f{sup +} - f{sup {minus}}, and growth/decay of the peak components, will be presented.

Bulletin of the American Physical Society•Dec 1, 1992•0 citations

Resolved-sideband cooling of a single Be + 9 ion in a cryogenic multi-Penning-trap for discrete symmetry tests with (anti-)protons

Juan M. Cornejo, Johannes Brombacher, Julia A. Coenders +5 more

Manipulating the motion of individual trapped ions at the single quantum level has become standard practice in radio-frequency ion traps, enabling sweeping advances in quantum information processing and precision metrology. The key step for motional-state engineering is ground-state cooling. Full motional control also bears great potential to explore another regime of sensitivities for fundamental physics tests in Penning traps. Here we demonstrate the key enabling step by implementing resolved-sideband cooling on the axial mode of a single Be + 9 ion in a 5 Tesla cryogenic Penning trap. The system has been developed for the implementation of high-precision antimatter experiments to test the fundamental symmetries of the standard model with the highest accuracy in the baryonic sector. We measure an axial phonon number of n ¯ z = 0.10 ( 4 ) after cooling and demonstrate that the axial heating rate in our system is compatible with the implementation of quantum logic spectroscopy of (anti-)protons. Published by the American Physical Society 2024

Physical Review Research•Sep 3, 2024•10 citations

Numerical simulations of three-dimensional ion crystal dynamics in a Penning trap using the fast multipole method

John Zaris, Wes Johnson, Athreya Shankar +2 more

We simulate the dynamics, including laser cooling, of three-dimensional (3-D) ion crystals confined in a Penning trap using a newly developed molecular dynamics-like code. The numerical integration of the ions’ equations of motion is accelerated using the fast multipole method to calculate the Coulomb interaction between ions, which allows us to efficiently study large ion crystals with thousands of ions. In particular, we show that the simulation time scales linearly with ion number, rather than with the square of the ion number. By treating the ions’ absorption of photons as a Poisson process, we simulate individual photon scattering events to study laser cooling of 3-D ellipsoidal ion crystals. Initial simulations suggest that these crystals can be efficiently cooled to ultracold temperatures, aided by the mixing of the easily cooled axial motional modes with the low frequency planar modes. In our simulations of a spherical crystal of 1000 ions, the planar kinetic energy is cooled to several millikelvin in a few milliseconds while the axial kinetic energy and total potential energy are cooled even further. This suggests that 3-D ion crystals could be well suited as platforms for future quantum science experiments.

arXiv:2405.13973•Journal of Plasma Physics•Apr 1, 2025•2 citations

Axialization of Laser Cooled Magnesium Ions in a Penning Trap

Hebe Powell, D. M. Segal, Richard Claude Thompson

We report the first demonstration of the axialization of laser cooled ions in a Penning trap. Axialization involves the application of a small radial quadrupole drive which couples the cyclotron and magnetron motions. This enhances the laser cooling, allowing tighter confinement of the ions to the central axis of the trap than is otherwise possible. Using an intensified charge-coupled device (ICCD) camera we have imaged the axialization process for the first time. For a single ion, we recorded a large decrease of the magnetron amplitude corresponding to a reduction in ion temperature of approximately 2 orders of magnitude to an upper limit of order 10 mK. We have discovered dynamics specific to the laser cooled system which depend critically on the axial drive frequency and amplitude.

Physical Review Letters•Aug 12, 2002•57 citations
We have performed systematic measurements of the resistive cooling behavior of bunches of highly charged ions in a Penning trap after injection from an external source. In particular, we have been able to measure the exponential cooling rate of the axial center-of-mass motion and experimentally show its linear dependence on the ion number within the bunch, as expected from theory. The common center-of-mass energy of the ions is reduced by more than four orders of magnitude on the time scale of milliseconds while the single-ion cooling occurs on the scale of seconds, representing a highly effective way to remove the dominating part of the ion kinetic energy. Published by the American Physical Society 2024
We perform a detailed experimental study of resistive cooling of large ensembles of highly charged ions such as Ar13+{\mathrm{Ar}}^{13+}Ar13+ in a cryogenic Penning trap. Different from the measurements reported by Vogel et al. [M. Vogel et al., Phys. Rev. A 90, 043412 (2014)], we observe purely exponential cooling behavior when conditions are chosen to allow collisional thermalization of the ions. We provide evidence that in this situation resistive cooling time constants and final temperatures are independent of the initial ion energy and that the cooling time constant of a thermalized ion ensemble is identical to the single-ion cooling time constant. For sufficiently high ion number densities, our measurements show discontinuities in the spectra of motional resonances which indicate a transition of the ion ensemble to a fluidlike state when cooled to temperatures below approximately 14 K. With the final ion temperature presently being 7.5 K, ions of the highest charge states are expected to form ion crystals by mere resistive cooling, in particular not requiring the use of laser cooling.
Externally, in an electron beam ion trap, generated Ar16+ ions were retrapped in a Penning trap and evaporatively cooled in their axial motion. The cooling was observed by a novel extraction technique based on the excitation of a coherent axial oscillation which yields short ion bunches of well-defined energies. The initial temperature of the ion cloud was decreased by a factor of more than 140 within 1 s, while the phase-space density of the coldest extracted ion pulses was increased by a factor of up to about 9.
A Penning trap which is optimized for transverse resistive cooling yields a cooling time constant for trapped He{sup +} ions of as low as 3 seconds, depending on cooling duty cycle. Opposite quadrants of the ring electrode resonate (Q=1800 at 7.4 MHz) with Nb/Ti inductors at 4.2 K. The f{prime} motion is resonantly cooled by operation at 2 Tesla axial field and trap voltages from 12 to 38 Volts. Ion signals are magnetically coupled to a 4 K GaAs fet preamplifier, wide-band 300 K amplifier and linear diode detection system. The rate of cooling is set by fractional time on resonance during sweep of the trap voltage. Shifting and broadening due to space charge are demonstrated. Other interesting features of the ion spectra, such as peak structure, response to heating by f{sup +} - f{sup {minus}}, and growth/decay of the peak components, will be presented.
Manipulating the motion of individual trapped ions at the single quantum level has become standard practice in radio-frequency ion traps, enabling sweeping advances in quantum information processing and precision metrology. The key step for motional-state engineering is ground-state cooling. Full motional control also bears great potential to explore another regime of sensitivities for fundamental physics tests in Penning traps. Here we demonstrate the key enabling step by implementing resolved-sideband cooling on the axial mode of a single Be + 9 ion in a 5 Tesla cryogenic Penning trap. The system has been developed for the implementation of high-precision antimatter experiments to test the fundamental symmetries of the standard model with the highest accuracy in the baryonic sector. We measure an axial phonon number of n ¯ z = 0.10 ( 4 ) after cooling and demonstrate that the axial heating rate in our system is compatible with the implementation of quantum logic spectroscopy of (anti-)protons. Published by the American Physical Society 2024
We simulate the dynamics, including laser cooling, of three-dimensional (3-D) ion crystals confined in a Penning trap using a newly developed molecular dynamics-like code. The numerical integration of the ions’ equations of motion is accelerated using the fast multipole method to calculate the Coulomb interaction between ions, which allows us to efficiently study large ion crystals with thousands of ions. In particular, we show that the simulation time scales linearly with ion number, rather than with the square of the ion number. By treating the ions’ absorption of photons as a Poisson process, we simulate individual photon scattering events to study laser cooling of 3-D ellipsoidal ion crystals. Initial simulations suggest that these crystals can be efficiently cooled to ultracold temperatures, aided by the mixing of the easily cooled axial motional modes with the low frequency planar modes. In our simulations of a spherical crystal of 1000 ions, the planar kinetic energy is cooled to several millikelvin in a few milliseconds while the axial kinetic energy and total potential energy are cooled even further. This suggests that 3-D ion crystals could be well suited as platforms for future quantum science experiments.
We report the first demonstration of the axialization of laser cooled ions in a Penning trap. Axialization involves the application of a small radial quadrupole drive which couples the cyclotron and magnetron motions. This enhances the laser cooling, allowing tighter confinement of the ions to the central axis of the trap than is otherwise possible. Using an intensified charge-coupled device (ICCD) camera we have imaged the axialization process for the first time. For a single ion, we recorded a large decrease of the magnetron amplitude corresponding to a reduction in ion temperature of approximately 2 orders of magnitude to an upper limit of order 10 mK. We have discovered dynamics specific to the laser cooled system which depend critically on the axial drive frequency and amplitude.