# Highly-polarizable ion in a Paul trap

## TL;DR

This paper investigates the effects of high polarizability in Rydberg ions trapped in a Paul trap, revealing significant Stark effect influences on trapping potential and demonstrating coherent control of Rydberg states.

## Contribution

It experimentally demonstrates the Stark effect on a highly-polarizable Rydberg ion in a Paul trap and explores its implications for quantum simulations and coherent control.

## Key findings

- Significant changes in trap stiffness and position due to Stark effect.
- First Rabi oscillations between low-lying and Rydberg states of an ion.
- Potential applications in quantum simulation and control.

## Abstract

Usually the influence of the quadratic Stark effect on an ion's trapping potential is minuscule and only needs to be considered in atomic clock experiments. In this work we excite a trapped ion to a Rydberg state with polarizability $\sim$~eight orders of magnitude higher than a low-lying electronic state; we find that the highly-polarizable ion experiences a vastly different trapping potential owing to the Stark effect. We observe changes in trap stiffness, equilibrium position and minimum potential, which can be tuned using the trapping electric fields. These effects lie at the heart of proposals to shape motional mode spectra, simulate quantum magnetism and coherently drive structural phase transitions; in addition we propose using these effects to simulate cosmological particle creation, study quantum fluctuations of work and minimize ion micromotion. Mitigation of Stark effects is important for coherent control of Rydberg ions; we illustrate this by carrying out the first Rabi oscillations between a low-lying electronic state and a Rydberg state of an ion.