Demonstration of a Tuneable Coupler for Superconducting Qubits Using Coherent, Time Domain, Two-Qubit Operations

TL;DR

This paper introduces a tunable superconducting coupler enabling long-distance, fast, and adjustable qubit interactions, which is crucial for scalable quantum computing architectures.

Contribution

A novel, self-contained, tunable coupler design that can connect superconducting qubits over long distances with high on/off ratio and rapid tuning capabilities.

Findings

Coupler achieves an on/off ratio of 1000.

Coupling strength can be tuned within nanoseconds.

Design allows integration with various quantum elements.

Abstract

A major challenge in the field of quantum computing is the construction of scalable qubit coupling architectures. Here, we demonstrate a novel tuneable coupling circuit that allows superconducting qubits to be coupled over long distances. We show that the inter-qubit coupling strength can be arbitrarily tuned over nanosecond timescales within a sequence that mimics actual use in an algorithm. The coupler has a measured on/off ratio of 1000. The design is self-contained and physically separate from the qubits, allowing the coupler to be used as a module to connect a variety of elements such as qubits, resonators, amplifiers, and readout circuitry over long distances. Such design flexibility is likely to be essential for a scalable quantum computer.