Spin-electric Berry phase shift in triangular molecular magnets

TL;DR

This paper demonstrates how an external electric field can induce a measurable Berry phase shift in a triangular magnetic molecule, enabling electric control of chiral qubits via geometric phase manipulation.

Contribution

It introduces a method to induce and control Berry phases in triangular magnetic molecules through electric fields, enabling potential quantum gate applications.

Findings

Berry phase depends on spin-orbit splitting and electric dipole moment.

Electric field amplitude controls the phase difference between spin states.

Phase shift can be measured using spin-echo techniques.

Abstract

We propose a Berry phase effect on the chiral degrees of freedom of a triangular magnetic molecule. The phase is induced by adiabatically varying an external electric field in the plane of the molecule via a spin-electric coupling mechanism present in these frustrated magnetic molecules. The Berry phase effect depends on spin-orbit interaction splitting and on the electric dipole moment. By varying the amplitude of the applied electric field, the Berry phase difference between the two spin states can take any arbitrary value between zero and $\pi$, which can be measured as a phase shift between the two chiral states by using spin-echo techniques. Our result can be used to realize an electric field induced geometric phase-shift gate acting on a chiral qubit encoded in the ground state manifold of the triangular magnetic molecule.