The coherence of quantum systems is the foundation upon which hardware for future information technologies is based. Quantum information is carried by units called quantum bits, or qubits. They can be used to secure electronic communications – and they enable very fast searches of databases. But qubits are also very unstable. Professors József Fortágh, Dieter Kölle and Reinhold Kleiner of Tübingen’s Institute of Physics have developed a new electronic component which will help to deal with this problem. The researchers’ long-term goal is to process, transfer and store superposition states such as the overlapping of the binary digits zero and one. The initial results of their work are to be published in the journal Nature Communicationson 29 August 2013.
The researchers aim to link two systems and draw on the advantages of both. Superconducting circuits, which are structured on microchips using standard technology, can process quantum information quickly but cannot store it for very long. By contrast, atoms, nature’s smallest electric circuits, can serve as a natural quantum storage unit. “In the future, this combination will allow us to transfer information from superconducting circuits into ensembles of atoms and store it,” says Professor József Fortágh.
The atoms are trapped in a magnetic field above the surface of the microchip. Because superconductors allow an electric current to flow without resistance, the current does not become weaker in a superconducting ring. Institute of Physics PhD students Helge Hattermann and Daniel Bothner along with postdoctoral researcher Simon Bernon have made use of this to construct a complex superconducting ring-circuit and a particularly stable storage space for atoms. And the researchers can test how long atoms remain in the quantum superposition states within the system – by using the atoms themselves as a clock.
Read more at: Phys.org