Hardware-Encoding Grid States in a Non-Reciprocal Superconducting Circuit

arXiv (Cornell University), vol. 11

Abstract

We present a circuit design composed of a non-reciprocal device and Josephson junctions whose ground space is doubly degenerate and the ground states are approximate codewords of the Gottesman-Kitaev-Preskill (GKP) code. We determine the low-energy dynamics of the circuit by working out the equivalence of this system to the problem of a single electron confined in a two-dimensional plane and under the effect of strong magnetic field and of a periodic potential. We find that the circuit is naturally protected against the common noise channels in superconducting circuits, such as charge and flux noise, implying that it can be used for passive quantum error correction. We also propose realistic design parameters for an experimental realization and we describe possible protocols to perform logical one- and two-qubit gates, state preparation and readout.

Authors 4

1. Martin Rymarz Aachen

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen

2. Stefano Bosco Aachen

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen

3. Alessandro Ciani
4. David Peter Divincenzo Aachen

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen