We have achieved a superconducting transition temperature (T_c) of 55 K in 27 at% B-doped Q-carbon. This value represents a significant improvement over previously reported T_c of 36 K in B-doped Q-carbon and is the highest T_c for conventional BCS (Bardeen–Cooper–Schrieffer) superconductivity in bulk carbon-based materials. The B-doped Q-carbon exhibits type-II superconducting characteristics with H_c2(0) ∼ 10.4 T, consistent with the BCS formalism. The B-doped Q-carbon is formed by nanosecond laser melting of B/C multilayered films in a super undercooled state and subsequent quenching. It is determined that ∼67% of the total boron exists with carbon in a sp³ hybridized state, which is responsible for the substantially enhanced T_c. Through the study of the vibrational modes, we deduce that higher density of states near the Fermi level and moderate to strong electron–phonon coupling lead to a high T_c of 55 K. With these results, we establish that heavy B doping in Q-carbon is the pathway for achieving high-temperature superconductivity.

中文翻译：

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B掺杂Q碳中高温超导（T _c = 55 K）的发现

我们已经在27at％的B掺杂Q碳中实现了55 K的超导转变温度（T _c）。该值表示比先前报道的B掺杂Q碳中的36 K的T _c显着提高，并且是散装碳基材料中常规BCS（Bardeen-Cooper-Schrieffer）超导性的最高T _c。掺B的Q碳具有H _c2（0）〜10.4 T的II型超导特性，这与BCS形式主义一致。B掺杂的Q碳是通过B / C多层膜的纳秒激光熔融过冷而形成的，然后进行淬火。经确定，sp ³中约有67％的硼与碳一起存在杂化状态，这是导致T _c显着提高的原因。通过对振动模态的研究，我们得出结论，费米能级附近较高的态密度以及中等至强的电子-声子耦合会导致55 K的高T _c。根据这些结果，我们得出结论，Q-碳是实现高温超导的途径。