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arXiv · 1501.04676

High-Fidelity Single-Shot Toffoli Gate via Quantum Control

Ehsan Zahedinejad·Joydip Ghosh·Barry C. Sanders
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Abstract

A single-shot Toffoli, or controlled-controlled-NOT, gate is desirable for classical and quantum information processing. The Toffoli gate alone is universal for reversible computing and, accompanied by the Hadamard gate, forms a universal gate set for quantum computing. The Toffoli gate is also a key ingredient for (non-topological) quantum error correction. Currently Toffoli gates are achieved by decomposing into sequentially implemented single- and two-qubit gates, which requires much longer times and yields lower overall fidelities compared to a single-shot implementation. We develop a quantum-control procedure to construct a single-shot Toffoli gate for three nearest-neighbor-coupled superconducting transmon systems such that the fidelity is 99.9% and is as fast as an entangling two-qubit gate under the same realistic conditions. The gate is achieved by a non-greedy quantum control procedure using our enhanced version of the Differential Evolution algorithm.

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Ehsan Zahedinejad, Joydip Ghosh, Barry C. Sanders. 2015-04-30. High-Fidelity Single-Shot Toffoli Gate via Quantum Control. https://doi.org/10.1103/physrevlett.114.200502

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