Technologies that exploit quantum phenomena such as controlled generation, manipulation and characterisation of quantum states and entanglement will be a radical departure from current ones. Such developments pose tremendous challenges, which a few years ago were considered nearly impossible to address. The EU-funded project 'Quantum networks via quantum optical systems' (QUANTNET) laid the mathematical foundations for developing quantum networks that are an essential part of future quantum technologies. The project's ultimate aim was to shed further insight into potentials and limitations of quantum-state manipulation of matter using quantum light–matter interfaces. Scientists derived various analytical relations that should help analyse the dephasing mechanism in simple quantum systems. These were based on the analytical solution of the Bloch equation for the two-state Demkov model. Another part of QUANTNET included the study of analytical factorisation methods and their applications for coherent quantum control based on a powerful transformation. This approach was generalised to handle cases in which two sub-sets have unequal detuning. Furthermore, scientists studied the coherent excitation of a simple two-state quantum system by an external field with a Lorentzian temporal shape and found exact and approximate solutions. Finally, the project found an exact solution that describes the Heston model, which is the most well-known model for stochastic processes in mathematical finance. Since QUANTNET's initiation, quantum information processing and stochastic processes became amongst the main research areas at the partner institute. Research into the latter fostered collaborations with private companies, focusing on stochastic modelling applications in the field of financial derivatives.
Quantum technologies, quantum network, quantum optical system, light-matter interface, two-state quantum system, stochastic process, quantum information processing