Abstract

The physical principle of nonlocality is of particular interest both for fundamental tests of quantum theory via Bell inequality violations and for many quantum information processing applications like quantum key distribution (QKD). Over the last decades, corresponding studies have been performed mostly on the basis of two-dimensional quantum states (qubits). In order to gain a deeper insight into the nature of nonlocality, more complex quantum states are studied by increasing the dimension of the state to d-dimensions (qudits). For QKD, for instance, it has been shown, at least theoretically, that increasing the dimension of the alphabet by using qudits increases the effective bit rate of the protocol as well as the resistance to noise compared to qubits.

© 2017 IEEE