Posted in 2019

Quantum Computational Supremacy

Last week Google and collaborators published a paper in which they claim to have achieved Quantum Supremacy , one of the major milestones in quantum computing. The idea of quantum supremacy is to use a programmable quantum device to perform a task that is out-of-reach for any classical computer Google claims to have solved a problem in seconds that would take tens of thousands of years on a state of the art supercomputer. The quantum supremacy experiment has been a long-standing milestone in the field of quantum computation, and as such, skepticism has arised; soon after publication of the article a group in IBM research has challenged the results [1].


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Net-Zero two-qubit gate published in Physical Review Letters

We have recently developed a new type of conditional-phase gate for transmon qubits providing several key improvements over standard flux-pulsing-based versions. The Net-Zero gate uses “leakage interference” to minimize leakage to non-computational states. The zero-average, bipolar shape of the pulse makes the gate robust to long timescale distortions in the flux control line and additionally provides an echo effect. We demonstrate a state-of-the-art conditional-phase gate of duration 40 ns achieving 99.1% fidelity and 0.1% leakage.


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