Pressure-induced enhancement of superconductivity and quantum criticality in the 12442-type hybrid-structure superconductor KCa2Fe4As4F2
| Autor: | Tetsujiro Eto, Yoshiya Uwatoko, Kento Ishigaki, Kazuyuki Matsubayashi, Jinguang Cheng, Zhi-Cheng Wang, Guanghan Cao, Bosen Wang, Jianping Sun |
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| Rok vydání: | 2019 |
| Předmět: |
Superconductivity
Physics Condensed matter physics Electronic correlation 02 engineering and technology Type (model theory) 021001 nanoscience & nanotechnology 01 natural sciences Tetragonal crystal system Electrical resistivity and conductivity 0103 physical sciences Fermi liquid theory 010306 general physics 0210 nano-technology Quantum Temperature coefficient |
| Zdroj: | Physical Review B. 99 |
| ISSN: | 2469-9969 2469-9950 |
| DOI: | 10.1103/physrevb.99.014501 |
| Popis: | We report a domelike superconductivity and quantum criticality in the 12442-type hybrid-structure superconductor $\mathrm{KC}{\mathrm{a}}_{2}\mathrm{F}{\mathrm{e}}_{4}\mathrm{A}{\mathrm{s}}_{4}{\mathrm{F}}_{2}$ under hydrostatic pressures up to 15 GPa. It is found that the superconducting transition temperature (${T}_{c}$) increases from $\ensuremath{\sim}33.5\phantom{\rule{0.16em}{0ex}}\mathrm{K}$ at ambient pressure to a maximum of $\ensuremath{\sim}36.5\phantom{\rule{0.16em}{0ex}}\mathrm{K}$ at 2 GPa in the background of enhanced resistivity of the $(\mathrm{K},\phantom{\rule{0.28em}{0ex}}\mathrm{Rb},\phantom{\rule{0.28em}{0ex}}\mathrm{Cs})\phantom{\rule{0.16em}{0ex}}\mathrm{C}{\mathrm{a}}_{2}\mathrm{F}{\mathrm{e}}_{4}\mathrm{A}{\mathrm{s}}_{4}{\mathrm{F}}_{2}$ at ambient pressure (AP), and then shows a slope change near 8 GPa with anomalous characteristics of resistivity. ${T}_{c}$ is found to be inversely proportional to the characteristic temperature of the coherence-incoherence crossover. The plots of resistivity at various temperatures and pressures and high-pressure x-ray diffraction confirm no pressure-induced half collapse of the tetragonal structure below 15 GPa. The pressure-induced crossover from non-Fermi liquid (the temperature exponent $n\ensuremath{\sim}1.05\ifmmode\pm\else\textpm\fi{}0.1$ at AP) to Fermi liquid ($n\ensuremath{\sim}1.92\ifmmode\pm\else\textpm\fi{}0.1$ at 15 GPa) is accompanied by the reduction of the linear temperature coefficient of normal-state resistivity, nearly two orders of magnitude compared to AP. These characteristics are ascribed to the weakening electronic correlation and/or critical fluctuations by pressure. |
| Databáze: | OpenAIRE |
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