Free-standing membranes are an exciting recent development in the field of complex oxides, allowing intrinsic material properties and phenomena to be probed in ways that would be difficult or otherwise inaccessible in epitaxially bound heterostructures. By employment of a water-soluble sacrificial layer of Sr₃Al₂O₆, strain-free ultrathin SrRuO₃ membranes have been fabricated that exhibit bulk lattice parameters and ferromagnetism at a Curie temperature of 150 K with the magnetic easy axis oriented 22° off the normal. The presence of sizable negative longitudinal magnetoresistance provides a direct signature of the decisive role played by Weyl Fermions in magnetotransport. In addition, a sign change between the strained films and free-standing SrRuO₃ membranes of in-plane transversal magnetotransport indicates a strong electromechanical coupling, resulting in a change of the Fermi velocity of Weyl Fermions. Our measurements provide a first insight into the magnetoelectric properties of SrRuO₃ membranes, highlighting the influence of the exfoliation process on structural, electronic, and magnetic degrees of freedom.

The development of “fault-tolerant” quantum computers, unaffected by noise and decoherence, is one of the fundamental challenges in quantum technology. One of the approaches currently followed is the realization of “topologically protected” qubits which make use of quantum systems characterized by a degenerate ground state of composite particles, known as “non-Abelian anyons”, able to encode and manipulate quantum information in a non-local manner. In this paper, we discuss the potential of quasi-two-dimensional electron gas (q2DEG) at the interface between band insulating oxides, like LaAlO3 and SrTiO3, as an innovative technological platform for the realization of topological quantum systems. Being characterized by a unique combination of unconventional spin-orbit coupling, magnetism, and 2D-superconductivity, these systems naturally possess most of the fundamental characteristics needed for the realization of a topological superconductor. These properties can be widely tuned by electric field effect acting on the orbital splitting and occupation of the non-degenerate 3dxy and 3dxz,yz bands. The topological state in oxide q2DEGs quasi-one-dimensional nanochannels could be therefore suitably controlled, leading to conceptual new methods for the realization of a topological quantum electronics based on the tuning of the orbital degrees of freedom.