Experiments

Quantum entanglement

We propose a measure of entanglement that can be computed for any pure state of an M-qubit system. The entanglement measure has the form of a distance that we derive from an adapted ap- plication of the Fubini-Study metric. This measure is invariant under local unitary transformations and defined as trace of a suitable metric that we derive, the entanglement metric g ̃. Furthermore, the analysis of the eigenvalues of g ̃ gives information about the robustness of entanglement.

The analogy between the classical Newton cradle, where the impulse of the mechanical momentum is transmitted along nearby spheres, and the realization through a Bose–Einstein condensate, where a wave-function disturbance is delivered along the lattice.

Disturbance of the wave-function that travels forward and backward in the uniform chain (hopping constant), with a superimposed Gaussian confining potential.