Transport of Spin Qubits with Donor Chains under Realistic Experimental Conditions

TL;DR

This paper models spin qubit transport in silicon donor chains under realistic conditions, demonstrating improved tolerance to placement errors and providing protocols for calibration and high-fidelity transport.

Contribution

It introduces a detailed model of donor chain spin transport considering experimental imperfections and proposes a calibration protocol for practical implementation.

Findings

Interface confinement improves placement error tolerance.

High-fidelity transport is achievable with realistic noise levels.

Protocols for chain initialization and calibration are provided.

Abstract

The ability to transport quantum information across some distance can facilitate the design and operation of a quantum processor. One-dimensional spin chains provide a compact platform to realize scalable spin transport for a solid-state quantum computer. Here, we model odd-sized donor chains in silicon under a range of experimental non-idealities, including variability of donor position within the chain. We show that the tolerance against donor placement inaccuracies is greatly improved by operating the spin chain in a mode where the electrons are confined at the Si-SiO$_2$ interface. We then estimate the required timescales and exchange couplings, and the level of noise that can be tolerated to achieve high fidelity transport. We also propose a protocol to calibrate and initialize the chain, thereby providing a complete guideline for realizing a functional donor chain and utilizing it for spin transport.