Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Magnetic polarization of the americium $J = 0$ ground state in
  AmFe$_{2}$   Trivalent americium has a non-magnetic ($J$ = 0) ground state arising from
the cancelation of the orbital and spin moments. However, magnetism can be
induced by a large molecular field if Am$^{3+}$ is embedded in a ferromagnetic
matrix. Using the technique of x-ray magnetic circular dichroism, we show that
this is the case in AmFe$_2$. Since $\langle J_z \rangle$ = 0, the spin
component is exactly twice as large as the orbital one, the total Am moment is
opposite to that of Fe, and the magnetic dipole operator $\langle T_{z}
\rangle$ can be determined directly; we discuss the progression of the latter
across the actinide series.

34
The categories of this paper are: chem-ph
33
The categories of this paper are: plasm-ph
36
The categories of this paper are: cmp-lg
19
The categories of this paper are: eess
3
The categories of this paper are: physics
31
The categories of this paper are: ao-sci
17
The categories of this paper are: q-fin
32
The categories of this paper are: atom-ph
20
The categories of this paper are: acc-phys
24
The categories of this paper are: dg-ga
29
The categories of this paper are: funct-an
12
The categories of this paper are: nucl-th
1
The categories of this paper are: cs
11
The categories of this paper are: hep-lat
21
The categories of this paper are: adap-org
9
The categories of this paper are: nlin