Adiabatic quantum state transfer in a semiconductor quantum-dot spin chain

TL;DR

This paper demonstrates a robust adiabatic quantum-state transfer method in semiconductor quantum-dot spin chains, achieving high fidelity transfer of single and two-spin states, crucial for scalable quantum computing.

Contribution

It introduces a new adiabatic transfer technique for spin qubits in quantum-dot chains, enabling high-fidelity, noise-resistant quantum state transfer over long distances.

Findings

Transfer of single- and two-spin states in less than 127 ns.

Estimated transfer fidelity exceeds 0.95 for experimental parameters.

Method is scalable and robust to noise and timing errors.

Abstract

Semiconductor quantum-dot spin qubits are a promising platform for quantum computation, because they are scalable and possess long coherence times. In order to realize this full potential, however, high-fidelity information transfer mechanisms are required for quantum error correction and efficient algorithms. Here, we present evidence of adiabatic quantum-state transfer in a chain of semiconductor quantum-dot electron spins. By adiabatically modifying exchange couplings, we transfer single- and two-spin states between distant electrons in less than 127 ns. We also show that this method can be cascaded for spin-state transfer in long spin chains. Based on simulations, we estimate that the probability to correctly transfer single-spin eigenstates and two-spin singlet states can exceed 0.95 for the experimental parameters studied here. In the future, state and process tomography will be required to verify the transfer of arbitrary single qubit states with a fidelity exceeding the classical bound. Adiabatic quantum-state transfer is robust to noise and pulse-timing errors. This method will be useful for initialization, state distribution, and readout in large spin-qubit arrays for gate-based quantum computing. It also opens up the possibility of universal adiabatic quantum computing in semiconductor quantum-dot spin qubits.