# Unconventional Superconductivity in the Novel Layered Superconductor FeTe-Se Investigated by $^{125}$Te NMR on the Single Crystal - Condensed Matter > Superconductivity

Unconventional Superconductivity in the Novel Layered Superconductor FeTe-Se Investigated by $^{125}$Te NMR on the Single Crystal - Condensed Matter > Superconductivity - Download this document for free, or read online. Document in PDF available to download.

Abstract: We have performed $^{125}$Te NMR on a single crystal of the novel layeredsuperconductor Fe${1.04}$Te${0.67}$Se${0.33}$ for the first time. The spinparts of the Knight shifts for both $H - a$, $H - c$ are suppressed in thesuperconducting state, indicating the spin singlet superconductivity. Atsuperconducting state, $1-T {1}$ shows the power-law behavior $\sim T^{3}$without any coherent peaks. Observations of the residual density of state andthe $T^{3}$-law indicate the presence of the line node in the superconductinggap. In the normal state, $1-T {1}T$ which probes the \textbf{q}-summation ofspin fluctuations enhances at low temperatures. Our results suggest that thesuperconductivity in Fe${1+\delta}$Te${1-x}$Se${x}$ is stabilized by thegrowth of the antiferromagnetic spin fluctuations as well as in FeSe.

Author: Chishiro Michioka, Hiroto Ohta, Mami Matsui, Jinhu Yang, Kazuyoshi Yoshimura, Minghu Fang

Source: https://arxiv.org/