Mathieu Control of the Effective Coupling in Superconducting Qubits

TL;DR

Mathieu control employs a non-resonant two-photon drive to dynamically and selectively tune interactions in superconducting qubits, enhancing quantum gate fidelity and enabling programmable quantum simulations.

Contribution

This work introduces Mathieu control, a novel method for continuous and selective tuning of qubit interactions using a two-photon drive, improving quantum gate control and simulation capabilities.

Findings

Enables full suppression and tuning of ZZ coupling.

Allows independent control in qubit-coupler-qubit systems.

Facilitates simulation of quantum magnetic phases.

Abstract

A common challenge in superconducting quantum circuits is the trade-off between strong coupling and computational subspace integrity. We present Mathieu control, which uses a non-resonant two-photon drive to create a selective nonlinear frequency shift. This shift modifies interactions while preserving qubit states, enabling continuous tuning of the ZZ coupling, including full suppression, and integrating single- and two-qubit gates with low leakage. For a qubit-coupler-qubit device, it allows independent ZZ control, facilitating a programmable Heisenberg (XXZ) Hamiltonian. Extended to a five-qubit chain, the system can be reconfigured to simulate dynamics of quantum magnetic phases. Mathieu control thus provides a framework for high-fidelity quantum logic and programmable simulation.