Title: ”Digital continuous-variable quantum key distribution”
Abstract: Continuous-variable quantum key distribution (CV-QKD) uses the continuous degrees of freedom provided by the amplitude and phase quadrature of the electro-magnetic field of light to perform quantum key distribution. A new paradigm in CV-QKD is to use digital signal processing (DSP) for adaptive quantum state generation and for detection. Using DSP CV-QKD systems can be built with a simple optical subsystem using local lasers as reference beams for quadrature receivers. In this talk I will introduce the concept of digital, i.e. DSP based, CV-QKD, how DSP is performed despite the low power of quantum states and discuss some experiments demonstrating the power of this approach. In particular I will discuss how to achieve 100 km
distance in fiber and how to implement high speed systems running at 10
GHz.
Biography: Tobias Gehring is an Associate Professor at the Department of Physics of the Technical University of Denmark (DTU) and co-founder of Alea Quantum Technologies, a Danish startup providing quantum random number generators. He received his degree in Physics in 2009 at the University of Heidelberg, Germany. In 2013 he obtained his PhD from the University of Hannover, Germany, after which he has been working as Postdoc and Assistant Professor at DTU. His research interests are continuous-variable quantum key distribution systems and quantum random number generators.