All-electric qubit control in heavy hole quantum dots via non-Abelian geometric phases

TL;DR

This paper introduces a method for all-electric, magnetic-field-free control of heavy hole spin qubits in quantum dots using non-Abelian geometric phases, enabling universal quantum operations with potentially long coherence times.

Contribution

It presents a novel approach to manipulate heavy hole qubits via non-Abelian geometric phases using electric fields, avoiding magnetic fields and preserving degeneracy.

Findings

Universal single-qubit gates achieved with electric quadrupole fields

Long coherence times expected due to preserved time reversal symmetry

No magnetic fields needed for qubit control

Abstract

We demonstrate how non-Abelian geometric phases can be used to universally process a spin qubit in heavy hole quantum dots in the absence of magnetic fields. A time dependent electric quadrupole field is used to perform any desired single qubit operation by virtue of non-Abelian holonomy. During the proposed operations, the degeneracy of the time dependent two level system representing the qubit is not split. Since time reversal symmetry is preserved and hyperfine coupling is known to be weak in spin qubits based on heavy holes, we expect very long coherence times in the proposed setup.