A New Quasi One-Dimensional Compound Ba3TiTe5 and Superconductivity Induced by Pressure

TL;DR

This study introduces a new quasi-one-dimensional compound Ba3TiTe5, explores its high-pressure induced superconductivity, and provides a phase diagram linking pressure, electronic phases, and superconducting properties.

Contribution

The paper reports the synthesis of Ba3TiTe5 and reveals pressure-induced superconductivity and phase transitions, offering insights into 1D to higher-dimensional electronic behavior under pressure.

Findings

Superconductivity appears above 8.8 GPa with Tc up to 6 K.

Superconductivity correlates with suppression of Umklapp gap and SDW/CDW fluctuations.

A comprehensive phase diagram of Ba3TiTe5 under pressure is established.

Abstract

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.