A precise CNOT gate in the presence of large fabrication induced variations of the exchange interaction strength

Abstract

We demonstrate how using two-qubit composite rotations a high fidelity controlled-NOT (CNOT) gate can be constructed, even when the strength of the interaction between qubits is not accurately known. We focus on the exchange interaction oscillation in silicon based solid-state architectures with a Heisenberg Hamiltonian. This method easily applies to a general two-qubit Hamiltonian. We show how the robust CNOT gate can achieve a very high fidelity when a single application of the composite rotations is combined with a modest level of Hamiltonian characterisation. Operating the robust CNOT gate in a suitably characterised system means concatenation of the composite pulse is unnecessary, hence reducing operation time, and ensuring the gate operates below the threshold required for fault-tolerant quantum computation.

arXiv comment9 pages, 8 figures

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Cited by in corpus (17)

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• Error correction optimisation in the presence of X/Z asymmetry
• Coherent electron transport by adiabatic passage in an imperfect donor chain
• Ultrahigh-fidelity composite rotational quantum gates
• Composite two-qubit gates
• Valley interference and spin exchange at the atomic scale in silicon
• Geometric Aspects of Composite Pulses
• Atomic-level Characterisation of Quantum Computer Arrays by Machine Learning
• Refocusing two qubit gate noise for trapped ions by composite pulses
• Minimal and Robust Composite Two-Qubit Gates with Ising-Type Interaction
• Valley filtering and spatial maps of coupling between silicon donors and quantum dots
• Fidelity Between Unitary Operators and the Generation of Gates Robust Against Off-Resonance Perturbations
• Quantum information processing in a spin-bus system of coupled chains
• Controlled-NOT logic with nonresonant Josephson phase qubits
• Modelling the effect of charge noise on the exchange interaction between spins
• On Binomial Summations and a Generalised Quantum SWAP Gate