Mitigating information leakage in a crowded spectrum of weakly anharmonic qubits

Abstract

A challenge for scaling up quantum processors using frequency-crowded, weakly anharmonic qubits is to drive individual qubits without causing leakage into non-computational levels of the others, while also minimizing the number of control lines. To address this, we implement single-qubit Wah-Wah control in a circuit QED processor with a single feedline for all transmon qubits, operating at the maximum gate speed achievable given the frequency crowding. Randomized benchmarking and quantum process tomography confirm alternating qubit control with $\le$1% average error per computational step and decoherence-limited idling of one qubit while driving another with a Wah-Wah pulse train.

arXiv comment5 pages, 4 figures; supplemental material with 5 figures; improved figure quality

References in corpus (1)

• Entanglement and Quantum Error Correction with Superconducting Qubits

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