Mitigating information leakage in a crowded spectrum of weakly anharmonic qubits

V. Vesterinen; O. -P. Saira; A. Bruno; L. DiCarlo

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arXiv · 1405.0450

Mitigating information leakage in a crowded spectrum of weakly anharmonic qubits

V. Vesterinen·O. -P. Saira·A. Bruno·L. DiCarlo

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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 $\leq$1% average error per computational step and decoherence-limited idling of one qubit while driving another with a Wah-Wah pulse train.

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V. Vesterinen, O. -P. Saira, A. Bruno, L. DiCarlo. 2014-05-02. Mitigating information leakage in a crowded spectrum of weakly anharmonic qubits. https://arxiv.org/abs/1405.0450

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