Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Cyclotron resonance study of quasiparticle mass and scattering rate in
  the hidden-order and superconducting phases of URu2Si2   The observation of cyclotron resonance in ultra-clean crystals of URu2Si2 [S.
Tonegawa et al., PRL 109, 036401 (2012)] provides another route besides quantum
oscillations to the determination of the bulk electronic structure in the
hidden order phase. We report detailed analyses of the resonance lines, which
fully resolve the cyclotron mass structure of the main Fermi surface sheets. A
particular focus is given to the anomalous splitting of the sharpest resonance
line near the [110] direction under in-plane magnetic-field rotation, which
implies peculiar electronic structure in the hidden order phase. The results
under the field rotation from [110] toward [001] direction reveal that the
splitting is a robust feature against field tilting from the basal plane. This
is in sharp contrast to the reported frequency branch alpha in the quantum
oscillation experiments showing a three-fold splitting that disappears by a
small field tilt, which can be explained by the magnetic breakdown between the
large hole sphere and small electron pockets. Our analysis of the cyclotron
resonance profiles reveals that the heavier branch of the split line has a
larger scattering rate, providing evidence for the existence of hot-spot
regions along the [110] direction. These results are consistent with the broken
fourfold rotational symmetry in the hidden-order phase, which can modify the
interband scattering in an asymmetric manner. We also extend our measurements
down to 0.7 K, which results in the observation of cyclotron resonance in the
superconducting state, where novel effects of vortex dynamics may enter. We
find that the cyclotron mass undergoes no change in the superconducting state.
In contrast, the quasiparticle scattering rate shows a rapid decrease below the
vortex-lattice melting transition temperature, which supports the formation of
quasiparticle Bloch state in the vortex lattice phase.

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The categories of this paper are: hep-th
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The categories of this paper are: adap-org
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The categories of this paper are: alg-geom
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The categories of this paper are: acc-phys
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The categories of this paper are: econ
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The categories of this paper are: hep-lat
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The categories of this paper are: chao-dyn
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The categories of this paper are: hep-ph
27
The categories of this paper are: comp-gas
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The categories of this paper are: supr-con
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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: bayes-an
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The categories of this paper are: q-alg
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The categories of this paper are: eess
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The categories of this paper are: math