Deterministic Generation of a Traveling Cat State with a Kerr Parametric Oscillator

Quantum computation with a network of Kerr parametric oscillators, or KPOs for short, has been proposed for the standard gate model [1,2] and adiabatic optimization [3]. Such a new machine is expected to be implemented with superconducting circuits [4,5]. A remarkable feature of a KPO is the ability to generate a Schödinger cat state deterministically via quantum adiabatic evolution. However, the cat state inside the KPO seems difficult to observe because of the large Kerr effect. Here we theoretically propose a method to release the cat state from the KPO without a tunable output coupler. As a result, a traveling cat state can be generated deterministically with a KPO and observed, e.g., by homodyne detection. We will also propose a superconducting-circuit implementation of the traveling-cat generator.
[1] H. Goto, Phys. Rev. A 93, 050301(R) (2016).
[2] S. Puri, S. Boutin and A. Blais, npj Quantum Information 3, 18 (2017).
[3]H. Goto, Sci. Rep. 6, 21686 (2016).
[4] S. E. Nigg, N. Lörch and R. P. Tiwari, Sci. Adv. 3, e1602273 (2017).
[5] S. Puri, C. K. Andersen, A. L. Grimsmo and A. Blais, Nat. Commun. 8, 15785 (2017).