Computing with light.

The Vision of the Quantum Computer

Photo: René Heilmann (IAP)

One of the most important requirements of our modern information society is the ability to rapidly and efficiently record, process and transmit large amounts of information and data. For this, computers are an indispensable tool; they allow, e.g., telephony, credit transfer, and the regulation of tight flight traffic. In recent years, however, it became evident that the technology available today reached its limits when managing the occurring amount of data. It seems inevitable to find radically new approaches in order to solve this problem.   One of the great visions of natural scientists is the optical quantum computer, with which complex problems can be computed by light. Such an apparatus would exhibit a computational power that is unprecedented by classical computers that are available today. A main challenge on the road to the quantum computer is the required miniaturization of the individual components, in order to integrate the circuits onto a single optical computer chip.   At the Institute of Applied Physics (IAP) of the Friedrich Schiller University Jena, scientists work towards the realization of such structures. By using ultra short laser pulses, complex networks of wave guiding structures are engraved in small glass chips, in which then single photons (the smallest unit of light) are launched. During their evolution through the network photons interact in a special way that is commonly called “quantum interference”. This is described by particular mathematical operations, which in turn can be determined by experimentally measuring the photon dynamics.   The concept of the quantum computer is very promising: Instead of computing a mathematical quantity with a classical computer, it is simply measured in a quantum computer. This allows considerably more efficient methods for data processing than in current machines. Scientists agree that these new approaches constitute a mile stone in the development of “future technology”, opening new and unexpected possibilities.

More information about the Institute for Applied Physics (IAP) at the Friedrich Schiller University Jena