Reducing unitary and spectator errors in cross resonance with optimized rotary echoes

2020/07/06 by Neereja Sundaresan, Isaac Lauer, Emily Pritchett +3 · 3 citations
Physics and Astronomy · #quant-ph

paper · pdf · doi:10.1103/prxquantum.1.020318

published as PRX Quantum 1, 020318 (2020)

arxiv created 2020/07/06 · arxiv updated 2021/01/04

Abstract

We present an improvement to the cross resonance gate realized with the addition of resonant, target rotary pulses. These pulses, applied directly to the target qubit, are simultaneous to and in phase with the echoed cross resonance pulses. Using specialized Hamiltonian error amplifying tomography, we confirm a reduction of error terms with target rotary -- directly translating to improved two-qubit gate fidelity. Beyond improvement in the control-target subspace, the target rotary reduces entanglement between target and target spectators caused by residual quantum interactions. We further characterize multi-qubit performance improvement enabled by target rotary pulsing using unitarity benchmarking and quantum volume measurements, achieving a new record quantum volume for a superconducting qubit system.

Cited by

• High-yield integration design of fixed-frequency superconducting qubit systems using siZZle-CZ gates
• Fast microwave-driven two-qubit gates between fluxonium qubits with a transmon coupler
• Implementing and benchmarking dynamically corrected gates on superconducting devices using space curve quantum control
• QubitHammer: Remotely Inducing Qubit State Change on Superconducting Quantum Computers