TY - JOUR
T1 - The Competition Between the CDW and the Superconducting State in Valence Skip Compounds
AU - Izumi Hase, Takashi Yanagisawa & Kenji Kawashima
JO - Communications in Computational Physics
VL - 3
SP - 773
EP - 780
PY - 2018
DA - 2018/03
SN - 23
DO - http://doi.org/10.4208/cicp.OA-2017-0060
UR - https://global-sci.org/intro/article_detail/cicp/10547.html
KW - Valence skip, CDW, superconductivity, electronic structure, RbTlX$_3$, SnX$_3$, BaBiO$_3$.
AB - <p style="text-align: justify;">In some superconductors the charge density wave (CDW) state is adjacent
to the superconducting state in the phase diagram. This CDW phase can be collapsed
either pressure or by chemical doping, depending on compound. Among them, in
so-called valence skip compounds, a large charge fluctuation with the large electron-phonon
interaction is expected. We performed a first-principle study and investigated
how the CDW gap is collapsed for several valence-skip compounds, i.e. SnX<sub>3</sub>, RbTlX<sub>3</sub>(X=F,Cl,Br,I) and CsTlI<sub>3</sub>. For all these compounds we found that the CDW gap is
rather robust for the uniform volume change, and on the contrary, the magnitude of
the CDW gap strongly depends on the position of the anion. We found that this CDW
gap is already collapsed at ambient pressure in SnBr<sub>3</sub>, SnI<sub>3 </sub>and CsTlI<sub>3</sub>.</p>