• Open Access

Reconfigurable Josephson Circulator/Directional Amplifier

K. M. Sliwa, M. Hatridge, A. Narla, S. Shankar, L. Frunzio, R. J. Schoelkopf, and M. H. Devoret
Phys. Rev. X 5, 041020 – Published 5 November 2015
PDFHTMLExport Citation

Abstract

Circulators and directional amplifiers are crucial nonreciprocal signal routing and processing components involved in microwave read-out chains for a variety of applications. They are particularly important in the field of superconducting quantum information, where the devices also need to have minimal photon losses to preserve the quantum coherence of signals. Conventional commercial implementations of each device suffer from losses and are built from very different physical principles, which has led to separate strategies for the construction of their quantum-limited versions. However, as recently theoretically, by establishing simultaneous pairwise conversion and/or gain processes between three modes of a Josephson-junction-based superconducting microwave circuit, it is possible to endow the circuit with the functions of either a phase-preserving directional amplifier or a circulator. Here, we experimentally demonstrate these two modes of operation of the same circuit. Furthermore, in the directional amplifier mode, we show that the noise performance is comparable to standard nondirectional superconducting amplifiers, while in the circulator mode, we show that the sense of circulation is fully reversible. Our device is far simpler in both modes of operation than previous proposals and implementations, requiring only three microwave pumps. It offers the advantage of flexibility, as it can dynamically switch between modes of operation as its pump conditions are changed. Moreover, by demonstrating that a single three-wave process yields nonreciprocal devices with reconfigurable functions, our work breaks the ground for the development of future, more complex directional circuits, and has excellent prospects for on-chip integration.

  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Received 27 March 2015

DOI:https://doi.org/10.1103/PhysRevX.5.041020

This article is available under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.

Published by the American Physical Society

Authors & Affiliations

K. M. Sliwa*, M. Hatridge, A. Narla, S. Shankar, L. Frunzio, R. J. Schoelkopf, and M. H. Devoret

  • Departments of Applied Physics and Physics, Yale University, New Haven, Connecticut 06520, USA

  • *To whom all correspondence should be addressed. katrina.sliwa@yale.edu
  • To whom all correspondence should be addressed. michel.devoret@yale.edu

Popular Summary

Reciprocity, the symmetry that exists upon exchanging the source and the observer, is a fundamental symmetry in physics. Breaking this symmetry is important when controlling the path flow of signals in an experiment. The two most important nonreciprocal devices in the microwave domain are the circulator and the directional amplifier. Circulators are three-port devices, and their nonreciprocal nature is based on the way in which microwave light interacts with magnetic fields. Directional amplifiers, on the other hand, are two-port devices that increase the power of signals entering the input port and forbid any transmission of signals entering the output port. Their directionality is typically based on semiconductor field-effect transistors, for which an input charge controls the flow of a current source. However, losses and noise typically render commercially available devices unsuitable for quantum applications. Here, we realize both types of directional functions from a single Josephson circuit with the same physical principle governing both functions in a setup that is flexible and essentially free of noise.

We experimentally demonstrate, at cryogenic temperatures (30 mK), that a Josephson-junction-based circuit can function as both a circulator and a directional amplifier by simply changing the pump conditions. We switch the role of the device by applying different sets of radio-frequency (GHz) drives to the circuit. In addition, we change, in situ, the direction of the signal flow by changing the relative phases of the drives. Elaborate signal-routing devices can be built by combining directional modules based on this feature.

We expect that our methodology, which involves nondegenerate three-wave mixing instead of large magnetic fields, provides a pathway for on-chip routing and processing of quantum signals from superconducting qubits.

Key Image

Article Text

Click to Expand

Supplemental Material

Click to Expand

References

Click to Expand
Issue

Vol. 5, Iss. 4 — October - December 2015

Subject Areas
Reuse & Permissions
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review X

Reuse & Permissions

It is not necessary to obtain permission to reuse this article or its components as it is available under the terms of the Creative Commons Attribution 3.0 License. This license permits unrestricted use, distribution, and reproduction in any medium, provided attribution to the author(s) and the published article's title, journal citation, and DOI are maintained. Please note that some figures may have been included with permission from other third parties. It is your responsibility to obtain the proper permission from the rights holder directly for these figures.

×

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×