First Quantum Teleportation Between Light and Matter

The concept of quantum teleportation - the disembodied complete transfer of the state of a quantum system to any other place - was first experimentally realised between two different light beams. Later it became also possible to transfer the properties of a stored ion to another object of the same kind. A team of scientist headed by Prof. Ignacio Cirac at MPQ and by Prof. Eugene Polzik at Niels Bohr Institute in Copenhagen has now shown that the quantum states of a light pulse can also be transferred to a macroscopic object, an ensemble of 10 to the power of 12 atoms (Nature, 4 October 2006). This is the first case of successful teleportation between objects of a different nature - the one representing a "flying" medium (light), the other a "stationary" medium (atoms). The result presented here is of interest not only for fundamental research, but also primarily for practical application in realising quantum computers or transmitting coded data (quantum cryptography)...