Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: High-Tc superconductivity in FeSe at high pressure: Dominant hole
  carriers and enhanced spin fluctuations   The importance of electron-hole interband interactions is widely acknowledged
for iron-pnictide superconductors with high transition temperatures (Tc).
However, high-Tc superconductivity without hole carriers has been suggested in
FeSe single-layer films and intercalated iron-selenides, raising a fundamental
question whether iron pnictides and chalcogenides have different pairing
mechanisms. Here, we study the properties of electronic structure in the
high-Tc phase induced by pressure in bulk FeSe from magneto-transport
measurements and first-principles calculations. With increasing pressure, the
low-Tc superconducting phase transforms into high-Tc phase, where we find the
normal-state Hall resistivity changes sign from negative to positive,
demonstrating dominant hole carriers in striking contrast to other FeSe-derived
high-Tc systems. Moreover, the Hall coefficient is remarkably enlarged and the
magnetoresistance exhibits anomalous scaling behaviors, evidencing strongly
enhanced interband spin fluctuations in the high-Tc phase. These results in
FeSe highlight similarities with high-Tc phases of iron pnictides, constituting
a step toward a unified understanding of iron-based superconductivity.

2
The categories of this paper are: math
0
The categories of this paper are: hep-ph
16
The categories of this paper are: stat
20
The categories of this paper are: acc-phys
14
The categories of this paper are: math-ph
34
The categories of this paper are: chem-ph
12
The categories of this paper are: nucl-th
30
The categories of this paper are: q-alg
7
The categories of this paper are: hep-th
31
The categories of this paper are: ao-sci
3
The categories of this paper are: physics
22
The categories of this paper are: chao-dyn
19
The categories of this paper are: eess
11
The categories of this paper are: hep-lat
36
The categories of this paper are: cmp-lg
9
The categories of this paper are: nlin