Exploring magnetic qubits for quantum computing
Unlike most approaches in quantum computing hardware that do not meet all criteria set for realistic implementation, the project focused on developing both new nanodevices and measurement techniques. Based on suitable materials, such as molecular clusters and antiferromagnetic nanoparticles, the magnetic quantum bits, or qubits, were extensively studied as far as their potential for hardware units is concerned. In order to get a better insight of the qubit behaviour of the magnetic clusters when working as logic gates, the interaction between microwave radiation and magnetic qubits was studied. Within this context, researchers tried to resolve two key issues, which involved the behaviour of our magnetic units as qubits and the superradiance emission. One of the key issues was the analysis of the electromagnetic radiation accompanying the fast demagnetisation process in molecular magnets. A large variety of different molecular magnets was used in order to correlate the chemical and nuclear properties of the magnetic unit with the probability of radiation emission. Additionally, researchers employed ultra-fast detection methods for the study of the magnetisation change and radiation detection. Under varying conditions, experiments allowed significant conclusions to be drawn on the influence of the temperature, magnetic field and number of molecules on the power emission of the electromagnetic radiation. By using a wide range of geometries, diameters, lengths and materials of waveguides, a better correlation of the power transmission with the waveguides was accomplished. Furthermore, new experiments were conducted for the second key issue, the spin tunnelling transitions in the case of an extremely high sweep of the bias magnetic field. In this case, the experiments displayed that quantum transitions do not adhere to the Landau Zener law as it was originally thought. This is mainly due to the transition of a huge number of spin levels at the same time, which can prove that superradiance emission takes place. The pioneering research on the interaction of microwave emission and qubits facilitated the development of nanoscale magnetic systems, which is a step forward to European Nanotechnology Information Devices (NID). Most importantly, these NIDs are expected to bridge the gap between conventional IT and the emerging quantum IT.
