Developed an innovative manufacturing method to make circuits of light with diamond: this is an important step towards a new generation of quantum technologies for future computers and communication channels that will allow encrypted information to be transferred securely.
The result is published in the ACS Photonics journal by the Institute of Photonics and Nanotechnology of the National Research Council (Cnr-Ifn) of Milan in collaboration with the German University of Ulm.
"In the diamond - observes Shane Eaton, a researcher at the Cnr-Ifn - there are, and can be suitably engineered, lattice defects capable of being used as qubits", or quantum bits, the basic elements of quantum information.
"These are color centers, reticular positions where an impurity is present and a carbon atom is missing, and in which it is possible to encode, control and manipulate quantum information in the form of qubits. This particular morphology, and the presence of these defects makes diamond a promising candidate for quantum technologies."
The Italian team, together with colleagues from the University of Ulm, demonstrated that it is possible to precisely place qubits inside photonic circuits formed by diamond lasers.
"These results - adds Eaton - arise from the first demonstration that femtosecond lasers (i.e. lasers that emit very short and close pulses) can create photonic connections in diamond, which are the fundamental building blocks necessary for quantum computing. Another fundamental ingredient is then that of creating qubits: with this new technique we have developed a chip integrated in diamond, capable of engineering light at the single photon level.The next step - concludes the researcher - will be
