Ion crystals in anharmonic traps

TL;DR

This paper explores the use of anharmonic quartic potentials to create more evenly spaced ion crystals for quantum computing, developing a variational method to analyze their ground state and phase transitions.

Contribution

It introduces a variational approach to study ion crystals in anharmonic traps, showing improved ion spacing uniformity and analyzing the zigzag transition.

Findings

Ions are more evenly spaced in quartic traps compared to harmonic traps.

The variational method effectively characterizes ground state properties.

The zigzag transition is analyzed in anharmonic potentials.

Abstract

There is currently intensive research into creating a large-scale quantum computer with trapped ions. It is well known that for a linear ion crystal in a harmonic potential, the ions near the center are more closely spaced compared to the ions near the ends. This is problematic as the number of ions increases. Here, we consider a linear ion crystal in an anharmonic potential that is purely quartic in position. We find that the ions are more evenly spaced compared to the harmonic case. We develop a variational approach to calculate the properties of the ground state. We also characterize the zigzag transition in an anharmonic potential.