Anagrafe della ricerca

Present implementations of Andreev spin qubits (ASQs) in electronic platforms are mostly based on Josephson junctions (JJs) where a semiconducting nanowire with strong spin-orbit coupling is contacted to two superconductors. Although the possibility to control and manipulate spin states via microwave radiation has been in principle demonstrated, the environment effects on the nanowire determine the short decoherence times obtained by various experiments. This currently represents a major limitation for efficient and large-scale applicability of this platform. TOPMASQ aims to propose a novel electron-based platform for ASQs, where the JJ is based on Topological Materials (TMs). Our goal is to exploit the spin texture and the topological protection of the TM electronic states to realize Andreev bound states that are spin split and robust to decoherence.  We shall explore two types of JJs, containing a Topological Insulator or a Topological Semimetal as a weak link. After determining the Andreev bound states as a function of the junction parameters, we shall analyze their coupling to microwave radiation and investigate the preparation and manipulation of the resulting ASQs. The coupling to the spin environment will be considered to deduce the decoherence time. TOPMASQ thus represents the challenging opportunity to bridge the fields of TMs and quantum dot optoelectronics to realize an ASQ, resulting in significant conceptual advances for nanoscience and technologies.