Flux Qubits and Readout Device with Two Independent Flux Lines

TL;DR

This paper demonstrates a scalable architecture for superconducting flux qubits with independent flux control using two on-chip flux lines, enabling coherent manipulation and readout of qubit states.

Contribution

It introduces a novel design with two independent flux bias lines for flux control, facilitating scalable quantum circuits with superconducting flux qubits.

Findings

Successful independent flux control of two qubits

Observation of Rabi oscillations and Ramsey fringes

Potential for scalable quantum computing architectures

Abstract

We report measurements on two superconducting flux qubits coupled to a readout Superconducting QUantum Interference Device (SQUID). Two on-chip flux bias lines allow independent flux control of any two of the three elements, as illustrated by a two-dimensional qubit flux map. The application of microwaves yields a frequency-flux dispersion curve for 1- and 2-photon driving of the single-qubit excited state, and coherent manipulation of the single-qubit state results in Rabi oscillations and Ramsey fringes. This architecture should be scalable to many qubits and SQUIDs on a single chip.