Andrew P. Higginbotham

Breaking Lorentz reciprocity with frequency conversion and delay

  1. Eric I. Rosenthal,
  2. Benjamin J. Chapman,
  3. Andrew P. Higginbotham,
  4. Joseph Kerckhoff,
  5. and K. W. Lehnert
We introduce a method for breaking Lorentz reciprocity based upon the non-commutation of frequency conversion and delay. The method requires no magnetic materials or resonant physics,
allowing for the design of scalable and broadband non-reciprocal circuits. With this approach, two types of gyrators — universal building blocks for linear, non-reciprocal circuits — are constructed. Using one of these gyrators, we create a circulator with > 15 dB of isolation across the 5 — 9 GHz band. Our designs may be readily extended to any platform with suitable frequency conversion elements, including semiconducting devices for telecommunication or an on-chip superconducting implementation for quantum information processing.
arxiv pdf

Reconfigurable re-entrant cavity for wireless coupling to an electro-optomechanical device

  1. Tim Menke,
  2. Peter S. Burns,
  3. Andrew P. Higginbotham,
  4. Nir S. Kampel,
  5. Robert W. Peterson,
  6. Katarina Cicak,
  7. Raymond W. Simmonds,
  8. Cindy A. Regal,
  9. and Konrad W. Lehnert
An electro-optomechanical device capable of microwave-to-optics conversion has recently been demonstrated, with the vision of enabling optical networks of superconducting qubits. Here
we present an improved converter design that uses a three-dimensional (3D) microwave cavity for coupling between the microwave transmission line and an integrated LC resonator on the converter chip. The new design simplifies the optical assembly and decouples it from the microwave part of the setup. Experimental demonstrations show that the modular device assembly allows us to flexibly tune the microwave coupling to the converter chip while maintaining small loss. We also find that electromechanical experiments are not impacted by the additional microwave cavity. Our design is compatible with a high-finesse optical cavity and will improve optical performance.
arxiv pdf