Abstract
HfTe3 single crystal undergoes a charge-density-wave (CDW) transition at TCDW = 93 K without the appearance of superconductivity (SC) down to 50 mK at ambient pressure. Here, we determined its CDW vector q = 0.91(1) a* + 0.27(1) c* via low-temperature transmission electron microscope and then performed comprehensive high-pressure transport measurements along three major crystallographic axes. Our results indicate that the superconducting pairing starts to occur within the quasi-one-dimensional (Q1D) -Te2-Te3- chain at 4–5 K but the phase coherence between the superconducting chains cannot be realized along either the b- or c-axis down to at least 1.4 K, giving rise to an extremely anisotropic SC rarely seen in real materials. We have discussed the prominent Q1D SC in pressurized HfTe3 in terms of the anisotropic Fermi surfaces arising from the unidirectional Te-5px electronic states and the local pairs formed along the -Te2-Te3- chains based on the first-principles electronic structure calculations.
Highlights
Charge-density-wave (CDW) and conventional superconductivity (SC) are both caused by strong electron-phonon coupling and Fermi surface (FS) instabilities, and the interplay between these two collective electronic phenomena has been a subject of extensive investigations over the past decades[1]
The former usually occurs in the low-dimensional materials and involves a periodic modulation of the conduction electron density and the underlying lattice; this will open a gap over part of the FS and lead to reduced conductivity
We report on a rare case that an intrinsic quasi-one-dimensional (Q1D) filamentary SC emerges and persists in a relatively wide temperature/pressure range when the CDW order of HfTe3 along the same crystallographic direction is completely suppressed by pressure
Summary
Charge-density-wave (CDW) and conventional superconductivity (SC) are both caused by strong electron-phonon coupling and Fermi surface (FS) instabilities, and the interplay between these two collective electronic phenomena has been a subject of extensive investigations over the past decades[1]. The polycrystalline HfTe3 sample shows the coexistence of the CDW order below TCDW ≈ 80 K and filamentary SC with Tc ≈ 2 K at ambient pressure[2].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
