Measuring the Wigner Angle with a Parametric Amplifier

Chad T. Rigetti, Doug Mcclure, Lafe Spietz +13 more

Ashfaq H. Khosa, Shi‐Yao Zhu, Muhammad Suhail Zubairy

P. K. Aravind

This paper presents a scheme for simulating and observing the Wigner angle using an optical parametric amplifier. The scheme is based on the observation that the dynamical symmetry group of the amplifier, which is SU(1,1), is locally isomorphic to the group SO(2,1) of Lorentz transformations in two space and one time dimension(s). It is shown how boosts and rotations in relativity can be realized as suitable operations on the amplifier, and a quantum-optical analog of the Wigner angle is identified. Using recently developed techniques for the generation and detection of squeezed states, a scheme is proposed for observing the optical analog of the Wigner angle. The feasibility of the scheme is evaluated, and its significance is discussed.

Alberto Casado

Matthijs H. J. de Jong

In this thesis, a we have designed and fabricated a Josephson Parametric Amplifier (JPA) using a new double-angle evaporation method without a Dolan bridge. We have found and resolved several issues in the fabrication procedure, but it requires further tuning before being fully functional. We have also simulated the behaviour of a general parametric amplifier with an additional Duffing non-linear term, and found that this term appears to limit the oscillation amplitude. We have attempted to characterize Josephson junctions fabricated with the new double-angle evaporation procedure, but without much success. Using a different fabrication method, a JPA was made and successfully characterized. The maximum measured gain is 16 dB, with a bandwidth of 1 MHz. The noise temperature is comparable to the cryostat temperature of 250 mK, but it was not characterized accurately.

Anthony G. St. Pierre, William A. Steele