Simultaneous Preparation of Two Optical Cat States Based on a Nondegenerate Optical Parametric Amplifier

Abstract

The cat state, known as the superposition of coherent states, has broad applications in quantum computation and quantum metrology. Increasing the number of optical cat states is crucial to implement complex quantum information tasks based on them. Here, two optical cat states are prepared simultaneously based on a nondegenerate optical parametric amplifier. By subtracting one photon from each of two squeezed vacuum states, two odd cat states with orthogonal superposition direction in phase space are prepared simultaneously, which have similar fidelity of 60% and amplitude of 1.2. Compared with the traditional method to generate two odd optical cat states based on two degenerate optical parametric amplifiers, only one nondegenerate optical parametric amplifier is applied in this experiment, which saves half of the quantum resources of nonlinear cavities. The presented results make a step toward preparing the four‐component cat state, which has potential applications in fault‐tolerant quantum computation.

Synchronization of Two Indirectly Coupled Singly Resonant Optical Parametric Oscillators

“…Systems of OPOs represent robust sources of coherent light and tunable radiation. In addition, OPOs are efficient sources of non-classical light states such as bi-partite entangled states, optical twin beams and squeezed vacuum states [3][4][5][6][7][8].…”

“…A qualitative perspective that stimulates the comprehension of SROs features is provided by investigation of the classical characteristics of light emitted from OPOs [14,15]. The SROs offer single frequency light sources with a narrow linewidth of the output radiation, making these devices highly recommended for a wide area of applications such as remote sensing, spectroscopy analysis, photoelectric detection, and optical frequency division [3][4][5][6][7][8][9][10][11][12][13]. In previous works, the self-sustained oscillations of the field in OPOs devices are treated as a limit-cycle oscillation but the type of the limit-cycle is not investigated [14,16,17].…”