Parallel Production of Quantum Memories
Over the past four decades, classical computers and classical communication networks have improved dramatically thanks to the ability to mass-produce tiny electronic components on individual silicon wafers. Quantum technologies could make similar strides, but it has been difficult to achieve the same parallel production for quantum memories—devices that help link quantum systems. Now Daniel Riedel of IonQ in Maryland and his colleagues have demonstrated a way to create multiple diamond-based quantum memory chips in parallel on a single silicon wafer [1].
Diamond quantum memories use microscopic defects in diamond crystals to trap electrons whose quantum states serve as qubits. These qubits are desirable because they retain their stored information for a relatively long time and can interact strongly with light, allowing their information to be written and read accurately. The parallel production of diamond quantum memories has faced two main challenges: High-quality diamond cannot be grown in wafer-scale sheets, and carving or etching individual bulk crystals is slow and unreliable. What’s more, photolithography, which enables the simultaneous printing of billions of components on a single silicon wafer, is currently infeasible.
To avoid those problems, the researchers implanted silicon atoms into several thin films of high-purity, single-crystal diamond. After high-temperature annealing, these atoms combined with lattice vacancies to form defects called silicon-vacancy centers. The team then deposited the films onto a silicon wafer, which could be prepatterned with the required electronic and photonic components. This approach produced hundreds of quantum memories at once with high uniformity. The researchers demonstrated that the silicon-vacancy centers and photons had the required strong interactions and that the performance of the memories was comparable to that of state-of-the art devices made using nonscalable bulk-diamond fabrication.
–Ryan Wilkinson
Ryan Wilkinson is a Corresponding Editor for Physics Magazine based in Durham, UK.
References
- D. Riedel et al., “Scalable photonic quantum interconnect platform,” Phys. Rev. X 16, 011063 (2026).