Revealing the microscopic structural and dynamic pictures of glasses is a long-standing challenge for scientists^1,2. Extensive studies on the structure and relaxation dynamics of glasses have constructed the current classical picture^3,4,5: glasses consist of some ‘soft zones’ of loosely bound atoms embedded in a tightly bound atomic matrix. Recent experiments have found an additional fast process in the relaxation spectra^6,7,8,9, but the underlying physics of this process remains unclear. Here, combining extensive dynamic experiments and computer simulations, we reveal that this fast relaxation is associated with string-like diffusion of liquid-like atoms, which are inherited from the high-temperature liquids. Even at room temperature, some atoms in dense-packed metallic glasses can diffuse just as easily as they would in liquid states, with an experimentally determined viscosity as low as 10⁷ Pa·s. This finding extends our current microscopic picture of glass solids and might help establish the dynamics–property relationship of glasses⁴.

^{揭示眼镜的微观结构和动态图片是科学家1,2}长期面临的挑战。对玻璃结构和弛豫动力学的广泛研究构建了当前的经典图^3,4,5：玻璃由嵌入紧密结合的原子矩阵中的松散结合原子的一些“软区”组成。最近的实验在弛豫光谱中发现了一个额外的快速过程^6,7,8,9，但这个过程的基本物理学仍不清楚。在这里，结合广泛的动态实验和计算机模拟，我们揭示了这种快速弛豫与液态原子的弦状扩散有关，这些原子继承自高温液体。即使在室温下，密集金属玻璃中的一些原子也可以像液态一样容易扩散，实验确定的粘度低至 10 ⁷  Pa·s。这一发现扩展了我们目前对玻璃固体的微观图景，并可能有助于建立玻璃的动力学特性关系⁴。