Quantum Crosstalk Robust Quantum Control
The prevalence of quantum crosstalk in current quantum devices poses
challenges for achieving high-fidelity quantum logic operations and reliable
quantum processing. Through quantum control theory, we develop an analytical
condition for achieving crosstalk-robust single-qubit control of multi-qubit
systems. We examine the effects of quantum crosstalk via a cumulant expansion
and develop a condition to suppress the leading order contributions to the
dynamics. The efficacy of the condition is illustrated in the domains of
quantum state preservation and noise characterization through the development
of crosstalk-robust dynamical decoupling and quantum noise spectroscopy (QNS)
protocols. Using the IBM Quantum Experience, crosstalk-robust state
preservation is demonstrated on 27 qubits, where a $3\times$ improvement in
coherence decay is observed for single-qubit product and multipartite entangled
states. Through the use of noise injection, we experimentally demonstrate
crosstalk-robust dephasing QNS on a seven qubit processor, where a $10^4$
improvement in reconstruction accuracy over ``cross-susceptible" alternatives
is found. Together, these experiments highlight the significant impact the
crosstalk mitigation condition can have on improving multi-qubit
characterization and control on current quantum devices.
Zeyuan Zhou Ryan Sitler Yasuo Oda Kevin Schultz Gregory Quiroz