Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Magnetic Field Tuning of Parallel Spin Stripe Order and Fluctuations
  near the Pseudogap Quantum Critical Point in
  La$_{1.36}$Nd$_{0.4}$Sr$_{0.24}$CuO$_4$   A quantum critical point in the single layer, hole-doped cuprate system
La$_{1.6-x}$Nd$_{0.4}$Sr$_x$CuO$_4$ (Nd-LSCO), near $x$ = 0.23 has been
proposed as an organizing principle for understanding high temperature
superconductivity. Our earlier neutron diffraction work on Nd-LSCO at optimal
and high doping revealed static parallel spin stripes to exist out to the QCP
and slightly beyond, at $x$ = 0.24 and 0.26. We examine more closely the
parallel spin stripe order parameter in Nd-LSCO in both zero magnetic field and
fields up to 8 T for H // c in these single crystals. In contrast to earlier
studies at lower doping, we observe that H //c in excess of $\sim$ 2.5 T
eliminates the incommensurate quasi-Bragg peaks associated with parallel spin
stripes. But this elastic scattering is not destroyed by the field; rather it
is transferred to commensurate {\textbf{Q} = 0} Bragg positions, implying that
the spins participating in the spin stripes have been polarized. Inelastic
neutron scattering measurements at high fields show an increase in the low
energy, parallel spin stripe fluctuations and evidence for a spin gap,
$\Delta_{spin}$= 3 $\pm$ 0.5 meV for Nd-LSCO with $x$ = 0.24. This is shown to
be consistent with spin gap measurements as a function of superconducting T$_C$
over five different families of cuprate superconductors, which follow the
approximate linear relation, $\Delta_{spin}$ = 3.5 k$_B$T$_C$.

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The categories of this paper are: q-alg
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The categories of this paper are: physics
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The categories of this paper are: nlin
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The categories of this paper are: q-bio
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The categories of this paper are: mtrl-th
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The categories of this paper are: hep-ph
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The categories of this paper are: astro-ph
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The categories of this paper are: funct-an
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The categories of this paper are: cs
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The categories of this paper are: bayes-an
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The categories of this paper are: eess
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The categories of this paper are: stat
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The categories of this paper are: atom-ph
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The categories of this paper are: quant-ph
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The categories of this paper are: alg-geom
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The categories of this paper are: solv-int