Dynamical control and novel quantum phases in impurity doped linear ion crystals

TL;DR

This paper investigates how impurity doping in linear ion crystals induces a quantum phase transition in phonon behavior, revealing non-analytic spectral features and controllable phase changes via laser-induced effective mass modifications.

Contribution

It demonstrates the emergence of a quantum phase transition driven by mass ratio variations and introduces a method to control this transition through adiabatic laser manipulation.

Findings

Identification of non-analytic eigenfrequency behavior at critical mass ratios

Observation of a quantum phase transition between condensed and conducting phonon phases

Proposal of laser-based control of impurity-induced quantum phases

Abstract

We explore the behavior of the phonon number distribution in an heterogeneous linear ion crystal. The presence of ion species with different masses changes dramatically the transverse energy spectrum, in such a way that two eigenfrequencies become non-analytic functions of the mass ratio in the form of a sharp cusp. This non-analyticity induces a quantum phase transition between condensed and conducting phase of the transverse local phonons. In order to continuously vary the mass ratio we adiabatically modify a locally applied laser field, exerting optical dipole forces which reduces the effective mass.