QuompleX is an international research consortium funded by the QuantERA programme, a European ERA-NET Cofund in Quantum Technologies. The consortium members include researchers from Austria, Italy, and the Netherlands, more information about whom can be found on the members page.
When we look into a mirror, we see a perfect image of ourselves that is formed by light reflecting off the mirror surface. In contrast, when light is incident on an uneven surface such as a layer of paint or a sugar cube, it scatters in many directions, usually leading to a scrambling of any information carried on the light beam. In recent years, scientists have achieved a staggering amount of control over how light propagates through such complex media, demonstrating feats such as looking through opaque scattering walls, and sending an entire image through a tiny optical fiber. The QuompleX project aims to use such techniques for the delicate task of manipulating quantum information carried by particles of light.
Quantum technologies such as quantum encryption and quantum computers promise as yet unattainable levels of information security and computing power. Such technologies rely on our ability to carefully control and transport quantum states of light, tasks that are usually achieved by conventional optical elements such as beam splitters or integrated photonic circuits. However, as the quantum states in question get more complex, the devices required to control them become harder and harder to use. In QuompleX, we turn this problem around by using commonly available scattering media such as multi-mode fibers as complex linear optical networks for generating, manipulating, and transporting multi-level quantum states of light.
In this manner, QuompleX will study the theoretical limits of quantum transformations possible with complex media, and apply them for designing multi-level quantum logic gates for light. In addition, the technologies developed in QuompleX will be used for the generation of complex, multi-photon entangled states of light and for implementing noise-robust quantum communication protocols with unprecedented levels of information security.