Structural phase transitions in multipole traps

Abstract

A small number of laser-cooled ions trapped in a linear radiofrequency multipole trap forms a hollow tube structure. We have studied, by means of molecular dynamics simulations, the structural transition from a double ring to a single ring of ions. We show that the single-ring configuration has the advantage to inhibit the thermal transfer from the rf-excited radial components of the motion to the axial component, allowing to reach the Doppler limit temperature along the direction of the trap axis. Once cooled in this particular configuration, the ions experience an angular dependency of the confinement if the local adiabaticity parameter exceeds the empirical limit. Bunching of the ion structures can then be observed and an analytic expression is proposed to take into account for this behaviour.

References in corpus (8)

• Radiofrequency multipole traps: Tools for spectroscopy and dynamics of cold molecular ions
• Fermionic collective excitations in a lattice gas of Rydberg atoms
• An ion ring in a linear multipole trap for optical frequency metrology
• How can a 22-pole ion trap exhibit 10 local minima in the effective potential?
• Evaporation of buffer gas-thermalized anions out of a multipole rf ion trap
• Ion dynamics in a linear radio-frequency trap with a single cooling laser
• Crystallization of ion clouds in octupole traps: structural transitions, core melting, and scaling laws
• Parallel ion strings in linear multipole traps

Cited by in corpus (6)

• Assembling a ring-shaped crystal in a microfabricated surface ion trap
• The physics and applications of strongly coupled plasmas levitated in electrodynamic traps
• Squeezed Coherent States of Motion for Ions Confined in Quadrupole and Octupole Ion Traps
• Stability and dynamics of ion rings in linear multipole traps
• Symmetry breaking in linear multipole traps
• Correcting symmetry imperfections in linear multipole traps