Electronic phase diagram of Fe$_{1+y}$Te$_{1-x}$Se$_{x}$ revealed by magnetotransport measurements
| Autor: | Shintaro Adachi, Y. Uezono, Yoshiki Nakanishi, Shotaro Hagisawa, Takao Watanabe, Masahito Yoshizawa, Yuta Koshika, Shojiro Kimura, Takumi Otsuka, Tomohiro Usui, Shunpei Yamaguchi, Nae Sasaki, Seya Sasaki |
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| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Superconductivity
Materials science Condensed matter physics Electronic correlation Condensed Matter - Superconductivity FOS: Physical sciences Statistical and Nonlinear Physics 02 engineering and technology Crystal structure 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Superconductivity (cond-mat.supr-con) Condensed Matter::Superconductivity 0103 physical sciences 010306 general physics 0210 nano-technology Phase diagram |
| Popis: | Among the Fe-based superconductors, Fe$_{1+y}$Te$_{1-x}$Se$_{x}$ is unique in that its crystal structure is the simplest and the electron correlation level is the strongest, and thus it is important to investigate the doping($x$)-temperature ($T$) phase diagram of this system. However, inevitably incorporated excess Fe currently prevents the establishment of the true phase diagram. We overcome the aforementioned significant problem via developing a new annealing method termed as "Te-annealing" wherein single crystals are annealed under Te vapor. Specifically, we conducted various magnetotransport measurements on Te-annealed superconducting Fe$_{1+y}$Te$_{1-x}$Se$_{x}$. We observed that crossover from the incoherent to the coherent electronic state and opening of the pseudogap occurs at high temperatures ($\approx$ 150 K for $x$ = 0.2). This is accompanied by a more substantial pseudogap and the emergence of a phase with a multi-band nature at lower temperatures (below $\approx$ 50 K for $x$ = 0.2) before superconductivity sets in. Based on the results, the third type electronic phase diagram in Fe-based high-$T_c$ superconductors is revealed. 10 pages, 5 figures, Proceedings of the International conference for ECSN-2019, Odessa, Ukraine |
| Databáze: | OpenAIRE |
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