New All-Fiber Device Simplifies Free-Space Based Quantum Key Distribution

(Phys.org) Researchers have developed a simple and stable device to generate the quantum states necessary for quantum key distribution. Quantum key distribution uses quantum properties of light such as polarization to encode and send a random key needed to decrypt encoded data. The method is exceptionally secure because any third-party intrusion is detectable.
Researchers from the University of Padova in Italy report that their all-fiber device can switch the polarization of light more than 1 billion times per second. The device is also self-compensating, making it insensitive to temperature and other environmental changes.
Giuseppe Vallone, who led this research within the QuantumFuture research group coordinated by co-author Paolo Villoresi. “Our scheme simplifies quantum key distribution for free-space communication—such as from satellites to Earth or between moving terminals— which is required to achieve a global quantum network.”