Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Symmetry of the Fermi surface and evolution of the electronic structure
  across the paramagnetic-helimagnetic transition in MnSi/Si(111)   MnSi has been extensively studied for five decades, nonetheless detailed
information on the Fermi surface (FS) symmetry is still lacking. This missed
information prevented from a comprehensive understanding the nature of the
magnetic interaction in this material. Here, by performing angle-resolved
photoemission spectroscopy on high-quality MnSi films epitaxially grown on
Si(111), we unveil the FS symmetry and the evolution of the electronic
structure across the paramagnetic-helimagnetic transition at T$_C$ $\sim$ 40 K,
along with the appearance of sharp quasiparticle emission below T$_C$. The
shape of the resulting FS is found to fulfill robust nesting effects. These
effects can be at the origin of strong magnetic fluctuations not accounted for
by state-of-art quasiparticle self-consistent GW approximation. From this
perspective, the unforeseen quasiparticle damping detected in the paramagnetic
phase and relaxing only below T$_C$, along with the persistence of the d-bands
splitting well above T$_C$, at odds with a simple Stoner model for itinerant
magnetism, open the search for exotic magnetic interactions favored by FS
nesting and affecting the quasiparticles lifetime.

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The categories of this paper are: nucl-th
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The categories of this paper are: ao-sci
1
The categories of this paper are: cs
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The categories of this paper are: quant-ph
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The categories of this paper are: solv-int
3
The categories of this paper are: physics
20
The categories of this paper are: acc-phys
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The categories of this paper are: astro-ph
34
The categories of this paper are: chem-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: math-ph
5
The categories of this paper are: gr-qc
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The categories of this paper are: funct-an
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The categories of this paper are: nucl-ex
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The categories of this paper are: patt-sol
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The categories of this paper are: adap-org