Illustration from Scientific Research

Scheme for controlling the strength of entanglement between left (L) and right (R) subsystems of the four-site array. After squeezing the symmetric mode (red), we transfer the squeezing into the antisymmetric mode (blue) by applying a local 180° spin rotation (green) to the right subsystem. Next, a global spinor rotation (purple) adjusts the angle of the squeezed quadrature. Finally, a second interaction pulse produces squeezing in the symmetric mode. The relative angle Φ between the squeezed axes of the collective modes determines the form of entanglement.

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