Systems and methods for cancellation of Crosstalk

A non-transitory computer readable storage medium storing one or more programs, the one or more programs comprising instructions of a digital computer system, which when executed by a digital computer system with one or more digital processors, cause the digital computer system to cause the system to reduce crosstalk during qubit idling and gates in a quantum computer system, the quantum computer system comprising a plurality of qudits, wherein each qudit in the plurality of qudits has a dimension of N, wherein N is a positive integer of 2 or greater, the method comprising, for each respective quantum operation in a set of at least one quantum operation, instructions for:

• (i) identifying a plurality of interacting systems within the plurality of qudits during the respective quantum operation, wherein each respective interacting system in the plurality of interacting systems comprises a corresponding subset of the plurality of qudits;
• (ii) identifying a corresponding set of components from the plurality of interacting systems;
• (iii) for each respective component in the corresponding set of components, evolving the respective component along with the respective components in the corresponding set of components that interact with the respective component in the respective quantum operation, thereby forming a plurality of maps for the respective set of components;
• (iv) calculating, for each respective component in the corresponding set of components, a corresponding marginal distribution using the corresponding map for the respective component, thereby computing a plurality of marginal distributions for the corresponding set of components;
• and
• (v) constructing a respective estimate of all or a portion of an entire Pauli error distribution for the respective quantum operation from the plurality of marginal distributions for the corresponding set of components;
• and
• (vi) generating, based on the constructed estimate, a set of tuned physical drive-field control parameters comprising an updated magnitude of a resonant n(x) quadrature, an updated magnitude of an off-resonant D(Y) quadrature, and an updated carrier signal phase, wherein the tuned control parameters are applied to the quantum computer system during execution of the quantum operation to reduce crosstalk and thereby improve infidelity by more than one order of magnitude for a model of superconducting qubits with realistic parameters.