Fast generation of Cat states in Kerr nonlinear resonators via optimal adiabatic control

TL;DR

This paper introduces a rapid and high-fidelity method for generating large, robust cat states in Kerr nonlinear resonators using optimal adiabatic control, advancing quantum information processing capabilities.

Contribution

It proposes a gradient-descent optimal adiabatic control technique that accelerates cat state creation in Kerr resonators, outperforming previous methods in speed and robustness.

Findings

Shorter preparation time for high-fidelity cat states

Enhanced robustness against photon loss

Ability to generate larger cat states with large initial detuning

Abstract

Macroscopic cat states have been widely studied to illustrate fundamental principles of quantum physics as well as their application in quantum information processing. In this paper, we propose a quantum speedup method for adiabatic creation of cat states in a Kerr nonlinear resonator via gradient-descent optimal adiabatic control. By simultaneously adiabatic tuning the the cavity detuning and driving field strength, the width of minimum energy gap between the target trajectory and non-adiabatic trajectory can be widen, which allows us to speed up the evolution along the adiabatic path. Compared with the previous proposal of preparing the cat state by only controlling two-photon pumping strength in a Kerr nonlinear resonator, our method can prepare the target state with much shorter time, as well as a high fidelity and a large non-classical volume. It is worth noting that the cat state prepared by our method is also robust against single-photon loss very well. Moreover, when our proposal has a large initial detuning, it will creates a large-size cat state successfully. This proposal of preparing cat states can be implemented in superconducting quantum circuits, which provides a quantum state resource for quantum information encoding and fault-tolerant quantum computing.