We introduce a new design concept for superconducting phase quantum bits (qubits) in which we explicitly separate the capacitive element from the Josephson tunnel junction for improved qubit performance. The number of two-level systems that couple to the qubit is thereby reduced by an order of magnitude and the measurement fidelity improves to 90%. This improved design enables the first demonstration of quantum state tomography with superconducting qubits using single-shot measurements.

arXiv:cond-mat/0602432Physical Review LettersAug 2, 2006226 citations

Phase Qubit on a Superconducting

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Jan 1, 20100 citations

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Superconducting Phase Qubits: Two-Qubit Tomography and Adjustable Coupling

Radoslaw C. Bialczak

Published Mar 18, 2010• 0 citations

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We experimentally demonstrate quantum process tomography of controlled-Z and controlled-NOT gates using capacitively coupled superconducting phase qubits. These gates are realized by using the

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