Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Orbital Hall effect in bilayer transition metal dichalcogenides: From
  the intra-atomic approximation to the orbital magnetic moment approach   Using an effective Dirac model, we study the orbital Hall effect (OHE) in
bilayers of transition metal dichalcogenides with 2H stacking (2H-TMD). We use
first-order perturbation theory in the interlayer coupling of the bilayer
system to obtain analytical expressions for the orbital Hall conductivity in
the linear response regime. We use two distinct descriptions of the orbital
angular momentum (OAM) operator: The first one is the intra-atomic
approximation that considers only the intrasite contribution to the OAM [Cysne
et al. Phys. Rev. Lett. 126, 056601 (2021)]. The second one uses the
Berry-phase formula of the orbital (valley) magnetic moment to describe the OAM
operator [Bhowal and Vignale, Phys. Rev. B 103, 195309 (2021)]. This approach
includes both intersite and intrasite contributions to the OAM. Our results
suggest that the two approaches agree qualitatively in describing the OHE in
bilayers of 2H-TMDs, although they present some quantitative differences. We
also show that interlayer coupling plays an essential role in understanding the
OHE in the unbiased bilayer of 2H-TMD. This coupling causes the Bloch states to
become combinations of states of individual layers, demanding the consideration
of the non-Abelian structure of the orbital magnetic moment. As we discuss
throughout the work, the emerging picture of transport of OAM in the unbiased
bilayer of 2H-TMDs based on OHE is very different from the usual picture based
on the valley Hall effect, shedding new lights on previous experimental
results. We also discuss the effect of the inclusion of a gate-voltage bias in
the bilayer system. Our work gives support to recent theoretical predictions on
OHE in two-dimensional materials.

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The categories of this paper are: chem-ph
3
The categories of this paper are: physics
19
The categories of this paper are: eess
17
The categories of this paper are: q-fin
2
The categories of this paper are: math
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The categories of this paper are: patt-sol
12
The categories of this paper are: nucl-th
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The categories of this paper are: nucl-ex
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The categories of this paper are: dg-ga
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The categories of this paper are: cmp-lg
21
The categories of this paper are: adap-org
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The categories of this paper are: ao-sci
16
The categories of this paper are: stat
22
The categories of this paper are: chao-dyn
6
The categories of this paper are: astro-ph
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The categories of this paper are: funct-an