Quantum information processing—which relies on spin defects or single-photon emission—has shown quantum advantage in proof-of-principle experiments including microscopic imaging of electromagnetic fields, strain and temperature in applications ranging from battery research to neuroscience. However, critical gaps remain on the path to wider applications, including a need for improved functionalization, deterministic placement, size homogeneity and greater programmability of multifunctional properties. Colloidal semiconductor nanocrystals can close these gaps in numerous application areas, following years of rapid advances in synthesis and functionalization. In this Review, we specifically focus on three key topics: optical interfaces to long-lived spin states, deterministic placement and delivery for sensing beyond the standard quantum limit, and extensions to multifunctional colloidal quantum circuits.

量子信息处理（依赖于自旋缺陷或单光子发射）已在原理验证实验中显示出量子优势，包括从电池研究到神经科学等应用中的电磁场、应变和温度的显微成像。然而，在更广泛的应用道路上仍然存在关键差距，包括需要改进的功能化、确定性布局、尺寸同质性和多功能属性的更大可编程性。经过多年在合成和功能化方面的快速进展，胶体半导体纳米晶体可以弥补许多应用领域的这些差距。在这篇综述中，我们特别关注三个关键主题：长寿命自旋态的光学接口、超出标准量子极限的传感的确定性放置和传输，以及多功能胶体量子电路的扩展。