Optimal control of circuit quantum electrodynamics in one and two dimensions

TL;DR

This paper demonstrates how optimal control techniques can enhance multi-qubit gate performance in 2D cavity-QED architectures, achieving significant speedups and scalability for quantum computing hardware.

Contribution

It introduces a method for applying optimal control to 2D cavity-qubit arrays, enabling faster, scalable, and more efficient multi-qubit gates in superconducting quantum architectures.

Findings

Speedups of up to three times under realistic conditions.

Control methods scale to large 2D grids and arbitrary qubit pairs.

Significant improvements over conventional sequential gate implementations.

Abstract

Optimal control can be used to significantly improve multi-qubit gates in quantum information processing hardware architectures based on superconducting circuit quantum electrodynamics. We apply this approach not only to dispersive gates of two qubits inside a cavity, but, more generally, to architectures based on two-dimensional arrays of cavities and qubits. For high-fidelity gate operations, simultaneous evolutions of controls and couplings in the two coupling dimensions of cavity grids are shown to be significantly faster than conventional sequential implementations. Even under experimentally realistic conditions speedups by a factor of three can be gained. The methods immediately scale to large grids and indirect gates between arbitrary pairs of qubits on the grid. They are anticipated to be paradigmatic for 2D arrays and lattices of controllable qubits.