Usually, when physicists perform quantum entanglement of particles – whether they are qubits, atoms, photons, electrons, etc. – these particles can be discerned. More recently, physicists have demonstrated the possibility of creating intricate particles that are completely identical. What is noteworthy, this confusion exists precisely because of the indistinguishability of the particles, without any interaction between them. But now, in a new work, physicists took one more step, showing that the entanglement of identical particles can be used and potentially applied to quantum applications
Rosario Lo Franco and Giuseppe Compagno of the University of Palermo in Italy published a paper on the benefits of entanglement of identical particles in the Physical Review Letters.
As physicists explain, in order for two independently prepared, identical particles to be tangled, they must be in physical proximity in space – or, technically speaking, the wave functions of the particles must at least partially overlap in space. If there is no spatial overlap, there will be no confusion. If the spatial overlap will be and measurements are made in the imposition area, there will be a certain probability of conditional entanglement. Entanglement will be certain only if the wave functions completely overlap in space.
What is most important in the new study is that physicists have developed a procedure for direct extraction of entanglement that occurs when wave functions completely overlap, with subsequent use of this confusion for different applications. To do this, they extended the concept of LOCC (local operations and classical communication), which is commonly used to quantify the confusion between discernible particles, to indistinguishable, identical particles. They needed to determine the spatial LOCC operations (sLOCC) so that they could identify the entanglement of identical particles and use them, for example, for the teleportation protocol.
“Our study shows that the main mechanism of entanglement can be realized by simply overlapping independent identical particles and access to entanglement through sLOCC operations, “says Lo Franco. “This operational approach is necessary for conducting experiments.”