Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Ultrafast spin-charge conversion at SnBi$_2$Te$_4$/Co topological
  insulator interfaces probed by terahertz emission spectroscopy   Spin-to-charge conversion (SCC) involving topological surface states (TSS) is
one of the most promising routes for highly efficient spintronic devices for
terahertz (THz) emission. Here, the THz generation generally occurs mainly via
SCC consisting in efficient dynamical spin injection into spin-locked TSS. In
this work, we demonstrate sizable THz emission from a nanometric thick
topological insultator (TI)/ferromagnetic junction - SnBi$_2$Te$_4$/Co -
specifically designed to avoid bulk band crossing with the TSS at the Fermi
level, unlike its parent material Bi$_2$Te$_3$. THz emission time domain
spectroscopy (TDS) is used to indicate the TSS contribution to the SCC by
investigating the TI thickness and angular dependence of the THz emission. This
work illustrates THz emission TDS as a powerful tool alongside angular resolved
photoemission spectroscopy (ARPES) methods to investigate the interfacial
spintronic properties of TI/ferromagnet bilayers.

21
The categories of this paper are: adap-org
0
The categories of this paper are: hep-ph
28
The categories of this paper are: alg-geom
26
The categories of this paper are: bayes-an
13
The categories of this paper are: quant-ph
31
The categories of this paper are: ao-sci
27
The categories of this paper are: comp-gas
10
The categories of this paper are: q-bio
14
The categories of this paper are: math-ph
30
The categories of this paper are: q-alg
12
The categories of this paper are: nucl-th
18
The categories of this paper are: econ
37
The categories of this paper are: supr-con
22
The categories of this paper are: chao-dyn
16
The categories of this paper are: stat
2
The categories of this paper are: math