Reducing Unitary and Spectator Errors in Cross Resonance with Optimized Rotary Echoes

Autor: Neereja Sundaresan, Isaac Lauer, Emily Pritchett, Easwar Magesan, Petar Jurcevic, Jay M. Gambetta
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: PRX Quantum, Vol 1, Iss 2, p 020318 (2020)
Druh dokumentu: article
ISSN: 2691-3399
DOI: 10.1103/PRXQuantum.1.020318
Popis: 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 multiqubit 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.
Databáze: Directory of Open Access Journals