The Josephson effect results from the coupling of two superconductors across a spacer such as an insulator, a normal metal or a ferromagnet to yield a phase coherent quantum state. However, in junctions with ferromagnetic spacers, very long-range Josephson effects have remained elusive. Here we demonstrate extremely long-range (micrometric) high-temperature (tens of kelvins) Josephson coupling across the half-metallic manganite La_0.7Sr_0.3MnO₃ combined with the superconducting cuprate YBa₂Cu₃O₇. These planar junctions, in addition to large critical currents, display the hallmarks of Josephson physics, such as critical current oscillations driven by magnetic flux quantization and quantum phase locking effects under microwave excitation (Shapiro steps). The latter display an anomalous doubling of the Josephson frequency predicted by several theories. In addition to its fundamental interest, the marriage between high-temperature, dissipationless quantum coherent transport and full spin polarization brings opportunities for the practical realization of superconducting spintronics, and opens new perspectives for quantum computing.

约瑟夫森效应源于两个超导体通过隔离物（例如绝缘体、普通金属或铁磁体）耦合产生相位相干量子态。然而，在与铁磁间隔物的连接中，非常长程的约瑟夫森效应仍然难以捉摸。_{在这里，我们展示了跨半金属亚锰酸盐 La 0.7} Sr _0.3 MnO ₃与超导铜酸盐 YBa ₂ Cu ₃ O ₇结合的超长程（微米）高温（数十开尔文）约瑟夫森耦合. 这些平面结，除了大的临界电流外，还显示出约瑟夫森物理学的特征，例如由磁通量量化驱动的临界电流振荡和微波激发下的量子锁相效应（夏皮罗步骤）。后者显示出几种理论预测的约瑟夫森频率异常加倍。除了其根本利益外，高温、无耗散量子相干传输与全自旋极化之间的结合为超导自旋电子学的实际实现带来了机会，并为量子计算开辟了新的前景。