Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Negative spin Hall magnetoresistance of Pt on the bulk easy-plane
  antiferromagnet NiO   We report on spin Hall magnetoresistance (SMR) measurements of Pt Hall bars
on the antiferromagnetic NiO(111) single crystal. An SMR with a sign opposite
of conventional SMR is observed over a wide range of temperatures as well as
magnetic fields stronger than 0.25T. The negative sign of the SMR can be
explained by the alignment of magnetic moments being almost perpendicular to
the external magnetic field within the easy plane (111) of the antiferromagnet.
This correlation of magnetic moment alignment and external magnetic field
direction is realized just by the easy-plane nature of the material without the
need of any exchange coupling to an additional ferromagnet. The SMR signal
strength decreases with increasing temperature, primarily due to the decrease
in N\'eel order by including fluctuations. An increasing magnetic field
increases the SMR signal strength as there are less domains and the magnetic
moments are more strongly manipulated at high magnetic fields. The SMR is
saturated at an applied magnetic field of $6$~T resulting in a spin-mixing
conductance of $\sim10^{18}~ \Omega^{-1}$m$^{-2}$, which is comparable to that
of Pt on insulating ferrimagnets such as yttrium iron garnet. An argon plasma
treatment doubles the spin-mixing conductance.

37
The categories of this paper are: supr-con
11
The categories of this paper are: hep-lat
31
The categories of this paper are: ao-sci
36
The categories of this paper are: cmp-lg
5
The categories of this paper are: gr-qc
29
The categories of this paper are: funct-an
13
The categories of this paper are: quant-ph
9
The categories of this paper are: nlin
34
The categories of this paper are: chem-ph
16
The categories of this paper are: stat
3
The categories of this paper are: physics
27
The categories of this paper are: comp-gas
18
The categories of this paper are: econ
21
The categories of this paper are: adap-org
22
The categories of this paper are: chao-dyn
10
The categories of this paper are: q-bio