Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Energy-gap driven low-temperature magnetic and transport properties in
  Cr$_{1/3}M$S$_2$ ($M$ = Nb or Ta)   The helimagnets Cr$_{1/3}M$S$_2$ ($M$ = Nb or Ta) have attracted renewed
attention due to the discovery of a chiral soliton lattice (CSL) stabilized in
an applied magnetic field, but reports of unusual low-temperature transport and
magnetic properties in this system lack a unifying explanation. Here we present
electronic structure calculations that demonstrate the materials are
half-metals. There is also a gap-like feature (width in range 40-100 meV) in
the density of states of one spin channel. This electronic structure explains
the low-temperature electronic and magnetic properties of Cr$_{1/3}M$S$_2$ ($M$
= Nb or Ta), with the gap-like feature particularly important for explaining
the magnetic behavior. Our magnetometry measurements confirm the existence of
this gap. Dynamic spin fluctuations driven by excitations across this gap are
seen over a wide range of frequencies (0.1 Hz to MHz) with AC susceptibility
and muon-spin relaxation ($\mu^+$SR) measurements. We show further how effects
due to the CSL in Cr$_{1/3}$NbS$_2$, as detected with $\mu^+$SR, dominate over
the gap-driven magnetism when the CSL is stabilized as the majority phase.

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The categories of this paper are: nucl-th
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The categories of this paper are: math-ph
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The categories of this paper are: nlin
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The categories of this paper are: dg-ga
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The categories of this paper are: astro-ph
33
The categories of this paper are: plasm-ph
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The categories of this paper are: hep-lat
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The categories of this paper are: alg-geom
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The categories of this paper are: atom-ph
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The categories of this paper are: physics
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The categories of this paper are: solv-int
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The categories of this paper are: cs
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The categories of this paper are: hep-ex
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The categories of this paper are: acc-phys
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The categories of this paper are: comp-gas
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The categories of this paper are: funct-an