Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Rapid and Precise Determination of Zero-Field Splittings by Terahertz
  Time-Domain Electron Paramagnetic Resonance Spectroscopy   Zero-field splitting (ZFS) parameters are fundamentally tied to the
geometries of metal ion complexes. Despite their critical importance for
understanding the magnetism and spectroscopy of metal complexes, they are not
routinely available through general laboratory-based techniques, and are often
inferred from magnetism data. Here we demonstrate a simple tabletop
experimental approach that enables direct and reliable determination of ZFS
parameters in the terahertz (THz) regime. We report time-domain measurements of
electron paramagnetic resonance (EPR) signals associated with THz-frequency
ZFSs in molecular complexes containing high-spin transition-metal ions. We
measure the temporal profiles of the free-induction decays of spin resonances
in the complexes at zero and nonzero external magnetic fields, and we derive
the EPR spectra via numerical Fourier transformation of the time-domain
signals. In most cases, absolute values of the ZFS parameters are extracted
from the measured zero-field EPR frequencies, and the signs can be determined
by zero-field measurements at two different temperatures. Field-dependent EPR
measurements further allow refined determination of the ZFS parameters and
access to the g-factor. The results show good agreement with those obtained by
other methods. The simplicity of the method portends wide applicability in
chemistry, biology and material science.

0
The categories of this paper are: hep-ph
22
The categories of this paper are: chao-dyn
30
The categories of this paper are: q-alg
15
The categories of this paper are: nucl-ex
12
The categories of this paper are: nucl-th
20
The categories of this paper are: acc-phys
24
The categories of this paper are: dg-ga
35
The categories of this paper are: mtrl-th
18
The categories of this paper are: econ
1
The categories of this paper are: cs
19
The categories of this paper are: eess
31
The categories of this paper are: ao-sci
17
The categories of this paper are: q-fin
10
The categories of this paper are: q-bio
5
The categories of this paper are: gr-qc
36
The categories of this paper are: cmp-lg