Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spin-momentum locked interaction between guided photons and surface
  electrons in topological insulators   The propagation of electrons and photons can respectively have the
spin-momentum locking effect which correlates the spin with the linear
momentum. For the surface electrons in three-dimensional topological insulators
(TIs), their spin is locked to the transport direction. For photons in optical
fibers and photonic waveguides, they carry transverse spin angular momentum
(SAM) which is also locked to the propagation direction. A direct connection
between the electronic and the optical spins occurs in TIs with lifted spin
degeneracy, which leads to spin-dependent selection rules of optical
transitions and results in phenomena such as circular photogalvanic effect
(CPGE). Here, we demonstrate an optoelectronic device that integrates a TI with
a photonic waveguide. Interaction between the photons in the
transverse-magnetic (TM) mode of the waveguide, which carries transverse SAM,
and the surface electrons in a Bi2Se3 layer generates a directional,
spin-polarized photocurrent. Because of optical spin-momentum locking, the
device works in a non-reciprocal way such that changing the light propagation
direction reverses the photon spin and thus the direction of the photocurrent
in the TI. This novel device provides a directional interface that directly
converts the photon propagation path to the direction and spin polarization of
the photo-excited surface current in the TI. It represents a new way of
implementing coupled spin-orbit interaction between electrons and photons and
may lead to significant applications in opto-spintronics and quantum
information processing.

24
The categories of this paper are: dg-ga
25
The categories of this paper are: patt-sol
35
The categories of this paper are: mtrl-th
15
The categories of this paper are: nucl-ex
21
The categories of this paper are: adap-org
9
The categories of this paper are: nlin
1
The categories of this paper are: cs
22
The categories of this paper are: chao-dyn
7
The categories of this paper are: hep-th
30
The categories of this paper are: q-alg
29
The categories of this paper are: funct-an
0
The categories of this paper are: hep-ph
28
The categories of this paper are: alg-geom
19
The categories of this paper are: eess
20
The categories of this paper are: acc-phys
32
The categories of this paper are: atom-ph