Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Pressure-induced superconductivity reentrant in transition metal
  dichalcogenide TiSe2   Through either elements intercalation or application of pressure, transition
metal dichalcogenide 1T-TiSe2 exhibits superconductivity in proximity to a
charge density wave (CDW) quantum critical point (QCP), thus providing an ideal
avenue to study the correlation between the two symmetry-breaking exotic
quantum electronic states. We report herein that, in addition to the well-known
superconducting dome that emerges within the low pressure range of 2 - 4 GPa
and peaks with the maximal Tc of about 1.8 K, the pressure induces another
separate superconducting transition starting around 15 GPa with a substantially
higher Tc that reaches 5.6 K at about 21.5 GPa. The high-pressure X-ray
diffraction and Raman spectroscopy measurements unveil that the
superconductivity reentrant is caused by a first-order structural phase
transition (from P-3m1 space group to Pnma space group), which is also
supported by the density functional theory calculation. A comparative
theoretical calculation also reveals that the conventional phonon-mediated
mechanism can account for the superconductivity of 1T-TiSe2 under low pressure,
while the electron-phonon coupling of 4O-TiSe2 under high pressure is too weak
to induce the superconductivity with a Tc as high as 5.6 K. This implies that
the emergent superconductivity in the 4O-TiSe2 may have an unconventional
origin. Our finding would open a new window toward the discovery of more exotic
quantum states in transition metal dichalcogenides via high pressure.

26
The categories of this paper are: bayes-an
16
The categories of this paper are: stat
1
The categories of this paper are: cs
30
The categories of this paper are: q-alg
35
The categories of this paper are: mtrl-th
21
The categories of this paper are: adap-org
22
The categories of this paper are: chao-dyn
28
The categories of this paper are: alg-geom
10
The categories of this paper are: q-bio
9
The categories of this paper are: nlin
20
The categories of this paper are: acc-phys
33
The categories of this paper are: plasm-ph
14
The categories of this paper are: math-ph
8
The categories of this paper are: hep-ex
17
The categories of this paper are: q-fin
29
The categories of this paper are: funct-an