
**Orbital Hall effect in two-dimensional materials**
T. G. Rappoport
Instituto de Telecomunicações, Lisboa, Portugal
Orbitronics, a next-generation technology utilizing orbital angular degrees of
freedom, 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.
This talk will explore orbital effects in solids and their potential
implications. I will concentrate on the orbital-Hall effect (OHE), which is
similar to the spin-Hall effect (SHE) in that it creates a transverse flow of
angular momentum due to a longitudinally applied electric field. However, it
emerges from the interplay between orbital properties and crystal symmetries,
and does not depend on spin-orbit coupling.
I will discuss different aspects of the OHE in 2D materials and show that
monolayers and bilayers of transition metal dichalcogenides (TMDs) exhibit OHE
in their insulating phase[1]. When cut along appropriate directions, the TMDs
host conducting edge-states, which cross their bulk gaps and can transport
orbital angular momentum [2]. Our results offer the possibility of using TMDs
for orbital current injection and orbital torque transfer that can surpass
their spin equivalents.
**References:**
[1] Tarik P. Cysne, Marcio Costa, Luis M. Canonico, M. Buongiorno Nardelli, R.
B. Muniz, Tatiana G. Rappoport , “Disentangling orbital and valley Hall
effects in bilayers of transition metal dichalcogenidesâ€, Phys. Rev. Lett.
126,056601(2021).
[2] Marcio Costa, Bruno Focassio, Tarik P. Cysne, Luis M. Canonico, Gabriel R.
Schleder, Roberto B. Muniz, Adalberto Fazzio, Tatiana G. Rappoport,
“Connecting Higher-Order Topology with the Orbital Hall Effect in Monolayers
of Transition Metal Dichalcogenidesâ€, arXiv:2205.00997
**Host:** L. Hueso