# Optimal control of two qubits via a single cavity drive in circuit quantum electrodynamics

## TL;DR

This paper demonstrates how optimal control techniques can be used to design high-fidelity, robust two-qubit gates in circuit quantum electrodynamics by driving a single cavity, with all simulations based on realistic experimental parameters.

## Contribution

It introduces a method to implement high-fidelity two-qubit gates in circuit QED using a single cavity drive optimized through control techniques, addressing spurious interactions.

## Key findings

- Achieved high-fidelity two-qubit gates with optimized pulse shapes.
- Demonstrated robustness against system parameter errors.
- Validated results with experimentally relevant parameters.

## Abstract

Optimization of the fidelity of control operations is of critical importance in the pursuit of fault-tolerant quantum computation. We apply optimal control techniques to demonstrate that a single drive via the cavity in circuit quantum electrodynamics can implement a high-fidelity two-qubit all-microwave gate that directly entangles the qubits via the mutual qubit-cavity couplings. This is performed by driving at one of the qubits' frequencies which generates a conditional two-qubit gate, but will also generate other spurious interactions. These optimal control techniques are used to find pulse shapes that can perform this two-qubit gate with high fidelity, robust against errors in the system parameters. The simulations were all performed using experimentally relevant parameters and constraints.