Towards orbitronics function in transition-metal-oxide heterostructures: a novel paradigm in oxide electronics – ORBIFUN

This project aims at unlocking the potentialities of the orbital-physics of Transition Metal Oxides (TMOs), establishing the basis for novel orbitronics function. The principal aspiration of this promising area of research is to switch between two electron orbital states via an external stimulus, such as electric-field. In this way orbital-polarization is used to convey the information paving the way to a novel and outstanding approach to design energy-saving oxide-based devices, where the shape of the occupied orbitals identifies the 0s and 1s.
The ultimate objective of ORBIFUN is gaining control over orbital-dependent currents in vertical junctions formed by two TMOs characterized by a tailorable or fixed orbital-polarizations: orbital-valve devices.
The innovative idea is to exploit ferroelectric polar-distortions that, in a reversal and remnant fashion, set an outstanding control over the orbital-polarization. Materials research and growth optimization are crucial points of this project, whose ambitious goal is based on three fundamental effects:
• Large orbital splitting at TMO/ferroelectric interface;
• Measurable ferroelectric-field control of the orbital-polarization;
• Orbital-dependent carrier transport resulting from the different orbital-polarization states on either side of the junction.
The plan is:
1. to realize prototypical orbital-valves with manganites, taking advantage from recent developments of the applicant;
2. to extend the application limits of the concept of an electric-field control of the orbital state in superconducting infinite-layer nickelates; on which the applicant has recently focused his interest.
Applicant’s expertise in growth and characterizations of several oxide families, enriched by the input of the built consortium, is an asset to guarantee the fulfilment of the planned research. Given the exploratory nature of ORBIFUN, new research opportunities beyond the planned objectives are most likely to take place as well.