A. Bruno

Mitigating information leakage in a crowded spectrum of weakly anharmonic qubits

  1. V. Vesterinen,
  2. O.-P. Saira,
  3. A. Bruno,
  4. and L. DiCarlo
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 ≤1 average error per computational step and decoherence-limited idling of one qubit while driving another with a Wah-Wah pulse train.
arxiv pdf