In Atomki, we are working on the device-independent framework of quantum information theory developing novel applications which exploit quantum correlations. Within this framework, our aim is to is to explore the ultimate limits what kind of tasks can and cannot be done with the aid of quantum correlations. The concrete objectives are
- Testing nonlocality in many-body systems
- Devising device-independent quantum information tasks
- Detecting Bell nonlocality from bound entanglement
Quantum nonlocality is one of the central aspects of quantum mechanics. This is the strange ability of quantum objects to synchronize actions over large distances in such a strong way, which could not have been resulted from any classical mechanism.
In addition to its fundamental interest, quantum nonlocality is instrumental in the emergent field of device-independent quantum information processing. In this new paradigm, local systems are regarded as black boxes, between which all the accessible information is given by a collection of measurement results, the only assumptions invoked being that individual devices are properly separated from each other and that inputs are chosen freely. Several quantum information tasks, such as quantum cryptography or randomness amplification can be accomplished in a device-independent manner. This new concept, for instance, allows novel key distribution protocols whose security is independent of the quantum states and measurements used to establish the key.