Using Sideband Transitions for Two-Qubit Operations in Superconducting Circuits

TL;DR

This paper demonstrates a method using sideband transitions to entangle superconducting qubits via a resonator, achieving high-fidelity Bell states and showing potential for scalable quantum gates.

Contribution

The authors introduce a novel pulse sequence utilizing sideband transitions for entangling superconducting qubits, advancing towards scalable quantum computation.

Findings

Achieved 75% fidelity Bell states.

Demonstrated entanglement distribution via sideband transitions.

Close agreement between experimental results and numerical simulations.

Abstract

We demonstrate time resolved driving of two-photon blue sideband transitions between superconducting qubits and a transmission line resonator. Using the sidebands, we implement a pulse sequence that first entangles one qubit with the resonator, and subsequently distributes the entanglement between two qubits. We show generation of 75% fidelity Bell states by this method. The full density matrix of the two qubit system is extracted using joint measurement and quantum state tomography, and shows close agreement with numerical simulation. The scheme is potentially extendable to a scalable universal gate for quantum computation.