Electrons carry both spin and orbital angular momentum. The search for phenomena that generate a flow of spin angular momentum—a spin current—has led to the development of spintronics. In contrast, the orbital counterpart of spin current—an orbital current—has largely been overlooked, and the generation of an orbital current remains challenging. Here we report the observation of orbital-current generation from magnetization dynamics: orbital pumping. We show that orbital pumping in nickel/titanium bilayers injects an orbital current into the titanium layer, which we detect through the inverse orbital Hall effect. Orbital pumping is the orbital counterpart of spin pumping, a versatile and powerful mechanism for spin-current generation. Our findings could, thus, provide a promising approach for generating orbital currents and could help in the development of the orbital analogue of spintronics: orbitronics.

电子携带自旋角动量和轨道角动量。对产生自旋角动量流（自旋流）的现象的探索导致了自旋电子学的发展。相比之下，自旋流的轨道对应物——轨道电流——在很大程度上被忽视了，轨道电流的产生仍然具有挑战性。在这里，我们报告了磁化动力学中轨道电流产生的观察：轨道泵浦。我们证明镍/钛双层中的轨道泵浦将轨道电流注入钛层，我们通过逆轨道霍尔效应检测到这一点。轨道泵浦是自旋泵浦的轨道对应物，是一种用于自旋电流产生的多功能且强大的机制。因此，我们的研究结果可以提供一种有前途的产生轨道电流的方法，并有助于开发自旋电子学的轨道模拟：轨道电子学。