Orbitronics

Conventional electronics relies on electric charge for processing information. In contrast, spintronics introduced the use of both spin and electric charge to create an energy efficient and stable alternative. However, spintronics requires the conversion of information between charge and spin currents, usually accomplished through spin-orbit coupling. Unfortunately, materials with strong spin-orbit coupling, such as gold, platinum, and tungsten, are scarce, expensive, and environmentally damaging to mine.

Orbitronics is a promising solution to these limitations. By manipulating the magnetic moment associated with the electrons' orbital angular momentum, rather than their spin, orbitronics eliminates the dependence on materials with strong spin-orbit coupling. This innovative approach broadens the range of materials that can be used for electrically controlling the magnetic moment of electrons. orbital_hall

Orbitronics has gained renewed interest for its potential use in logic and memory devices. By harnessing the orbital angular momentum as an information carrier, this technology has the potential to revolutionize the field of information processing.

The research line seeks to leverage the accumulated knowledge in spintronics to establish a new paradigm in information processing by harnessing orbitronics, the interplay between the charge and orbital angular momentum of carriers. This research line focuses on practical aspects of orbital transport, such as orbital relaxation and interactions with light, to lay the theoretical groundwork and drive successful experiments in this emerging field, which remains largely unexplored in 2D materials.

To achieve these goals, the research combines techniques developed in the manipulation of orbital angular momentum in optics with material science and spintronics. The research is structured into two interconnected research lines, employing numerical methods as valuable tools. The first research line aims to identify the physical requirements for efficient orbital transport in 2D materials, ranging from the generation of robust orbital currents with orbital Hall effect on insulators to the characterization of orbital relaxation phenomena. The second research line focuses on the study of light-matter interactions, investigating the optical properties of 2D materials, as means to generate and detect orbital currents.

By integrating these complementary research lines, we aim to pave the way for novel information processing capabilities enabled by orbitronics in 2D materials.

Highlighted publications:

  • “First light on orbitronics as a viable alternative to electronics (News and Views)", T. G. Rappoport, Nature 619, 38 (2023). (news and views).
  • "Connecting Higher-Order Topology with the Orbital Hall Effect in Monolayers of Transition Metal Dichalcogenides ", Marcio Costa, Bruno Focassio, Tarik P. Cysne, Luis M. Canonico, Gabriel R. Schleder, Roberto B. Muniz, Adalberto Fazzio, Tatiana G. Rappoport; Phys. Rev. Lett. 130, 116204(2023).
  • "Disentangling orbital and valley Hall effects in bilayers of transition metal dichalcogenides", Tarik P. Cysne, Marcio Costa, Luis M. Canonico, M. Buongiorno Nardelli, R. B. Muniz, Tatiana G. Rappoport; Phys. Rev. Lett. 126, 056601 (2021).