Quasi One-Dimensional Compound and Superconductivity Induced by Pressure*

Ba₃TiTe₅ was synthesized at HP/HT with infinite face-sharing octahedral TiTe₆ chains and Te chains along the c axis, exhibiting a strong 1D characteristic structure. The calculations confirmed the 1D conductor charaterization, and can be considered a starting point to explore the exotic physics induced by pressure to move the 1D conductor to a high-dimensional metal. High-pressure techniques were employed to study the emerging physics dependent on interchain hopping, such as the Umklapp scattering effect, spin/charge density wave, superconductivity and non-Fermi liquid behavior. Finally, a complete phase diagram was plotted. The superconductivity emerges at 9GPa, near which the Umklapp gap is mostly suppressed. T_c is enhanced and reaches a maximum of 6K at 37 GPa, where the SDW or 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 the Umklapp gap and that the enhancement of the T_c is related to the fluctuation of the SDW or CDW.