QUANTOX — QUANtum Technologies with 2D-OXides

The development of "fault tolerant" quantum computation, unaffected by noise and decoherence, is one of the fundamental challenge in quantum technology. One of the approaches currently followed is the realization of "topological protected" qubits which make use of quantum systems characterized by a degenerate ground state composed by collective composite particles, known as "non-Abelian anyons", able to encode and manipulate quantum information in a nonlocal manner. An example of such non-Abelian anyons are Majorana zero energy modes (MZMs), which have been reported in NbN/InSb/NbN hybrid junctions composed by a InSb semiconducting nanowire (characterized by large spin orbit coupling) proximised by NbN s-wave superconducting leads. Here we propose two-dimensional oxides (2D-oxides) as an innovative technological platform for the realization of topological quantum systems. Our idea is to exploit the unique combination of unconventional Rashba spin-orbit coupling (SOC), 2D-magnetism, superconductivity (SC) and high-mobility in the 2D electron gas (2DEG) at the interface between oxide insulators, as for instance LaAlO3 (LAO) and SrTiO3 (STO). The basic element of this technology is a quasi-one dimensional nano-channel, whose properties can be locally tuned using electric field effect to create both topological and non-topological superconducting sections, and metallic or even insulating tunnelling barriers. This platform has all the characteristics for the practical realization of theory-based proposals for topological quantum computation, and important fundamental and technological advantages. 2D-oxides technology allows a top-down approach for nanodevices realization fully scalable to complex systems including a large number of qubits. All the ingredients necessary for creating, manipulating and braiding zero energy Majorana modes can be realized using the same material and incorporated in the device layout in a seamless way. Moreover, the strong sensitivity of the LAO/STO 2DEG to the orbital splitting and occupation of the non-degenerate 3dxy and 3dxz,yz bands, allows the realization of a topological quantum electronics controlled by the orbital degrees of freedom. Our project is aimed at establishing oxide 2DEGs as a viable platform for the realization of topological quantum computers, thus launching a new technological approach to the realization of "fault tolerant" quantum computers. QUANTO project is committed to the realization and study of a novel technological platform, based on the oxide nanotechnology, for topological quantum computation in the area of quantum computation and quantum information science (areas 2 and 3 of the call). Moreover, QUANTO project will introduce novel ideas and methods in quantum science and technologies (area 3), by demonstration of braiding in non-abelian systems using the orbital control of the superconducting order parameter and of the Rashba spin-orbit coupling. This new method relies on the strong sensitivity of oxide 2DEGs to the orbital of degrees of freedom, i.e. to the orbital splitting and occupation of 3d-orbitals derived bands. The development and implementation of quantum-gates based on the oxide technology will have several expected impact on the QUANTERA call: (i) establish the fundaments of a new technological platform for the realization of topological quantum computers which promise robustness in the presence of environmental decoherence due its " fault tolerant" nature; (ii) enhance scalability of quantum information technology to multi-qubits operation by providing a nanotechnology process based on thin-film growth and top-down lithography; (iii) realization of industrially relevant device technology through an interdisciplinary approach combining materials science and device physics with quantum information. Possible future on-chip integration with semiconducting technology and RSFQ electronics will also be considered.