We develop an experimental tool to investigate the order parameter of superconductors by combining point-contact spectroscopy measurement with high-pressure technique. It is demonstrated for the first time that planar point-contact spectroscopy measurement on noncentrosymmetric superconducting PbTaSe 2 single crystals is systematically subjected to hydrostatic pressures up to 12.1 kbar. Under such a high pressure, the normal-state contact resistance is sensitive to the applied pressure, reflecting the underlying variation of contact transparency upon pressures. In a superconducting state, the pressure dependence of the energy gap Δ 0 and the critical temperature T c for gap opening/closing are extracted based on a generalized Blond–Tinkham–Klapwijk model. The gap ratio 2 Δ 0 / k B T c indicates a crossover from weak coupling to strong coupling in electron pairing strength upon pressu...

中文翻译：

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超导PbTaSe 2单晶的压力依赖点接触光谱

我们开发了一种通过将点接触光谱测量与高压技术相结合来研究超导体有序参数的实验工具。首次证明非中心对称超导PbTaSe 2单晶的平面点接触光谱测量系统地承受高达12.1 kbar的静水压力。在如此高的压力下，常态接触电阻对施加的压力敏感，反映出接触透明度在压力下的潜在变化。在超导状态下，基于广义Blonde-Tinkham-Klapwijk模型，提取了能隙Δ0的压力依赖性和间隙打开/关闭的临界温度T c。