The bipolaronic insulating (BI) state can cause the emergent superconducting phase when the strength of electron–phonon interaction is deliberately reduced. In this report, we have investigated electronic phase diagram of the well-known BI compound Ti₄O₇ by analyzing the transport properties of over 40 epitaxial-film samples. The diagram captures the systematic suppression of the BI state with increasing the number of doped electrons and a superconducting dome located under the BI state. The coexistence of the BI and superconducting states suggests the bipolaronic superconductivity in Ti₄O₇ epitaxial films.

中文翻译：

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Ti4O7外延薄膜中双极性绝缘状态下的超导圆顶

当故意降低电子-声子相互作用的强度时，双极性绝缘状态（BI）会导致出现超导相。在本报告中，我们通过分析40多个外延膜样品的传输特性，研究了著名的BI化合物Ti ₄ O ₇的电子相图。该图通过增加掺杂电子的数量和位于BI状态下的超导圆顶捕获了BI状态的系统抑制。BI和超导状态的共存表明Ti ₄ O ₇外延膜中的双极超导性。