All-Electric Quantum State Transfer via Spin-Orbit Phase Matching

TL;DR

This paper demonstrates an all-electric control protocol for long-distance quantum state transfer in hole-spin qubits, overcoming spin-orbit induced limitations through phase matching and axis alignment.

Contribution

It introduces a method to achieve near-perfect quantum state transfer by tuning electric fields, enabling robust transport in hole-spin quantum dot systems.

Findings

Identified discrete spin-orbit phase-matching conditions for state transfer.

Electric field direction control suppresses excitation non-conserving processes.

Achieved robust quantum state transfer without fine tuning.

Abstract

Semiconductor hole-spin qubits offer a promising route to quantum computation due to their weak hyperfine interaction, and strong intrinsic spin-orbit coupling enabling electric control of qubits. Scalable architectures, however, require coherent long-distance quantum state transfer, which is hindered in these systems by spin-orbit induced anisotropic exchange. Here we show that this limitation can be overcome by using an all-electric control protocol. By tuning the electric field strength, we identify discrete spin-orbit phase-matching conditions that restore near-perfect state transfer, independent of the rotation axis. Complementarily, controlling the electric field direction aligns the spin-orbit axis, suppressing excitation non-conserving processes and enabling robust transfer without fine tuning. Our results establish that electrical control of spin-orbit phases through either magnitude tuning or axis alignment as a practical route for robust quantum information transport in hole-spin quantum dot arrays.