Speaker
Description
As quantum computers advance, the need for quantum networks becomes more apparent. In order to realize a quantum internet, we need to connect processors over long distances. With quantum cryptography, security levels in communication could then be raised to unprecedented levels.
Due to the exponential loss of photons in fibers over long distances, an optical quantum network relies on quantum repeaters that allow for qubit storage with sufficiently long coherence times. A thoroughly investigated platform for such repeaters is the silicon-vacancy (SiV) color center in diamond. At temperatures below 100 millikelvin, this defect exhibits spin memory long enough to enable entanglement over a distance of 500 kilometers. The major drawback of this platform, despite its impressive performance, is the extremely low temperature requirement which demands expensive dilution refrigeration.
A promising candidate to overcome this limitation is the NiV color center in diamond. Due to stronger spin-orbit coupling, the ground state splitting of Nickel is larger, making the spin qubit stable at temperatures up to ~2K. These temperatures are reached with a much more affordable and transportable setup.
Here we present recent efforts for chip integration of NiV color centers.