title: Phase-modulated decoupling and error suppression in qubit-oscillator systems.
abstract: We present a scheme designed to suppress the dominant source of infidelity in entangling gates between quantum systems coupled through intermediate bosonic oscillator modes. Such systems are particularly susceptible to residual qubit-oscillator entanglement at the conclusion of a gate period that reduces the fidelity of the target entangling operation. We demonstrate how the exclusive use of discrete shifts in the phase of the field moderating the qubit-oscillator interaction is sufficient to both ensure multiple oscillator modes are decoupled and to suppress the effects of fluctuations in the driving field. This approach is amenable to a wide variety of technical implementations including geometric phase gates in superconducting qubits and the Molmer-Sorensen gate for trapped ions. We present detailed example protocols tailored to trapped-ion experiments and demonstrate that our approach has the potential to enable multiqubit gate implementation with a significant reduction in technical complexity relative to previously demonstrated protocols.
authors: ARC Centre for Engineered Quantum Systems, School of Physics, The University of Sydney, New South Wales 2006 Australia.
authors: Todd J
authors: TJ
authors: Green
authors: ARC Centre for Engineered Quantum Systems, School of Physics, The University of Sydney, New South Wales 2006 Australia.
authors: Michael J
authors: MJ
authors: Biercuk