Analysis and mitigation of residual exchange coupling in linear spin qubit arrays

Abstract

In recent advancements of quantum computing utilizing spin qubits, it has been demonstrated that this platform possesses the potential for implementing two-qubit gates with fidelities exceeding 99.5%. However, as with other qubit platforms, it is not feasible to completely turn qubit couplings off. This study aims to investigate the impact of coherent error matrices in gate set tomography by employing a double quantum dot. We evaluate the infidelity caused by residual exchange between spins and compare various mitigation approaches, including the use of adjusted timing through simple drives, considering different parameter settings in the presence of charge noise. Furthermore, we extend our analysis to larger arrays of exchange-coupled spin qubits to provide an estimation of the expected fidelity. In particular, we demonstrate the influence of residual exchange on a single-qubit $Y$ gate and the native two-qubit SWAP gate in a linear chain. Our findings emphasize the significance of accounting for residual exchange when scaling up spin qubit devices and highlight the tradeoff between the effects of charge noise and residual exchange in mitigation techniques.

15 pages, 8 figures

References in corpus (5)

• Fidelity of quantum operations
• Fault-Tolerant Quantum Computation For Local Non-Markovian Noise
• Pair-wise decoherence in coupled spin qubit networks
• High-fidelity CNOT gate for spin qubits with asymmetric driving using virtual gates
• Nonadiabatic quantum control of quantum dot arrays with fixed exchange using Cartan decomposition

Cited by in corpus (5)

• 12-spin-qubit arrays fabricated on a 300 mm semiconductor manufacturing line
• Scalable Parity Architecture With a Shuttling-Based Spin Qubit Processor
• Highly Tunable Two-Qubit Interactions in Si/SiGe Quantum Dots by Interchanging the Roles of Qubit-Defining Gates
• Maximizing the nondemolition nature of a quantum measurement via an adaptive readout protocol
• Robust shaped pulses for arrays of superconducting or semiconductor spin qubits with fixed Ising coupling