APS Tip Sheet: Improving quantum information processing

January 6, 2020 – Scientists use basic units of quantum information, called qubits, to share information across quantum devices. Qubits store information by simultaneously inhabiting two quantum-mechanical states. Now, scientist Elben et al. have established a new protocol to crosscheck if two quantum computers are producing equal results. The researchers tested their protocol on experimental data from a previous experiment involving highly entangled 10-qubit quantum states. They found the process required notably fewer measurements than needed in quantum tomography, in which simulators must reconstruct each entire quantum state. The process will enable these devices to better measure and compare the closeness — or fidelity — of multiple quantum states across devices and time. The study could improve the way quantum information processing simulators and computers transmit information.

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Cross-platform verification of intermediate scale quantum devices

Andreas Elben*, Benoît Vermersch, Rick van Bijnen, Christian Kokail, Tiff Brydges, Christine Maier, Manoj K. Joshi, Rainer Blatt, Christian F. Roos, Peter Zoller

*[email protected]