Southwest Quantum Information and Technology

Quantum Heisenberg interaction between Floquet qubits

Presenting Author: Long Nguyen, University of California Berkeley
Contributing Author(s): Yosep Kim, Akel Hashim, Noah Goss, Brian Marinelli, Ravi Naik, John Mark Kreikebaum, David Santiago, Irfan Siddiqi

Our work displays a solution to engineer the XXZ quantum Heisenberg model in fixed-frequency qubits via the concept of Floquet engineering. We show that by applying off-resonant photon drives, we can adiabatically connect fixed-frequency qubits' eigenstates in the lab frame to the corresponding Floquet states which are tunable in the dressed frame. Subsequently, simultaneous controls of the transverse XX and longitudinal ZZ interactions between the Floquet qubits can be achieved by varying the pulses' amplitudes, relative phases, and durations. We demonstrate the robustness and practicality of this protocol by calibrating and characterizing two-qubit iSWAP, CZ, SWAP, and three-qubit CCZ gate with fidelities of 99.32%, 99.7%, 98.93%, and 92.4%, respectively. Our results illustrate the viability of tailoring qubit frequencies in the dressed frames via application of periodic drives, provides a reliable avenue to engineer the XXZ Heisenberg interaction in quantum systems with fixed frequencies, and adds crucial quantum gates to the toolbox of current state-of-the-art superconducting devices.

(Session 5 : Thursday from 5:00 pm - 7:00 pm)