  We report systematical studies of a new quasi-one-dimensional (1D) compound
Ba3TiTe5 and the high-pressure induced superconductivity therein. Ba3TiTe5 was
synthesized at high pressure and high temperature. It crystallizes into a
hexagonal structure (P63/mcm), which consists of infinite face-sharing
octahedral TiTe6 chains and Te chains along the c axis, exhibiting a strong 1D
characteristic structure. The first-principles calculations demonstrate that
Ba3TiTe5 is a well-defined 1D conductor and thus, it can be considered a
starting point to explore the exotic physics induced by pressure via enhancing
the interchain hopping to move the 1D conductor to a high dimensional metal.
For Ba3TiTe5, high-pressure techniques were employed to study the emerging
physics dependent on interchain hopping, such as the Umklapp scattering effect,
spin/charge density wave (SDW/CDW), superconductivity and non-Fermi Liquid
behavior. Finally, a complete phase diagram was plotted. The superconductivity
emerges from 8.8 GPa, near which the Umklapp gap is mostly suppressed. Tc is
enhanced and reaches the maximum ~6 K at about 36.7 GPa, where the spin/charge
density wave (SDW/CDW) is completely suppressed, and a non-Fermi Liquid
behavior appears. Our results suggest that the appearance of superconductivity
is associated with the fluctuation due to the suppression of Umklapp gap and
the enhancement of Tc is related with the fluctuation of the SDW/CDW.
