The discovery of artificial gauge fields controlling the dynamics of uncharged particles that otherwise elude the influence of standard electromagnetic fields has revolutionised the field of quantum simulation. Hence, developing new techniques to induce these fields is essential to boost quantum simulation of photonic structures. Here, we experimentally demonstrate the generation of an artificial gauge field in a photonic lattice by modifying the topological charge of a light beam, overcoming the need to modify the geometry along the evolution or impose external fields. In particular, we show that an effective magnetic flux naturally appears when a light beam carrying orbital angular momentum is injected into a waveguide lattice with a diamond chain configuration. To demonstrate the existence of this flux, we measure an effect that derives solely from the presence of a magnetic flux, the Aharonov-Bohm caging effect, which is a localisation phenomenon of wavepackets due to destructive interference. Therefore, we prove the possibility of switching on and off artificial gauge fields just by changing the topological charge of the input state, paving the way to accessing different topological regimes in a single structure, which represents an important step forward for optical quantum simulation.

人工规范场的发现可以控制不带电粒子的动力学，从而避免标准电磁场的影响，这彻底改变了量子模拟领域。因此，开发诱发这些场的新技术对于促进光子结构的量子模拟至关重要。在这里，我们通过实验证明了通过修改光束的拓扑电荷在光子晶格中生成人工规范场，克服了沿演化修改几何形状或施加外部场的需要。特别是，我们表明，当携带轨道角动量的光束注入具有菱形链结构的波导晶格时，有效磁通量自然出现。为了证明这种通量的存在，我们测量了仅源自磁通量存在的效应，即阿哈罗诺夫-玻姆笼效应，这是由于相消干涉而导致的波包局域化现象。因此，我们证明了仅通过改变输入态的拓扑电荷即可打开和关闭人工规范场的可能性，为在单一结构中访问不同的拓扑状态铺平了道路，这代表着光量子模拟向前迈出了重要的一步。