Topological protection provides a route to protect fragile quantum states, which are otherwise very sensitive to noise and thermal fluctuations of the environment that surrounds them. In 2010, it was theoretically proposed that such topological protection could be achieved in hybrid nanoscale devices consisting of superconductor and semiconductor layers. The resulting quantum states, owing to the similarities with the theory of Ettore Majorana from the 1930’s, are called Majorana modes. The experimental search for the Majorana modes has been fueled by the possibility to reach hardware quantum error correction, vital for scalable quantum computation and would eliminate the huge number of physical quantum bits required for an error corrected logical quantum bit needed in the case of other types of quantum hardware.
The goal of the project is to investigate a novel direction in the creation of Majorana states, which is based on a linear array of quantum dots with superconducting leads. The key advantage of this physical implementation is the control of the device parameters, which will allow us to reproducibly map the topological phase diagram of the system. In order to achieve this overarching goal, we will utilize low frequency as well as microwave domain measurement techniques and will build our devices using narrow gap III-V semiconductors together with conventional metallic superconductors. Furthermore, we will investigate the non-locality of the Majorana bound states, and in doing so, we will demonstrate superconducting molecular states spanning between neighboring quantum dots.
Our experimental progress in the field of topological state of matter, quantum computation methods and cryogenic technologies together substantiates the scientific and societal impact of the project. To strengthen this impact and to lower the access threshold of our results, we have adhered to the principles of open science and open hardware development throughout the project.
