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.
@article{arxiv.1007.2219,
title = {Demonstration of a Tuneable Coupler for Superconducting Qubits Using Coherent, Time Domain, Two-Qubit Operations},
author = {R. C. Bialczak and M. Ansmann and M. Hofheinz and M. Lenander and E. Lucero and M. Neeley and A. D. O'Connell and D. Sank and H. Wang and M. Weides and J. Wenner and T. Yamamoto and A. N. Cleland and J. M. Martinis},
journal= {arXiv preprint arXiv:1007.2219},
year = {2013}
}