Quantum photonic integrated scalable memory

The HUB-Exp subproject aims to experimentally realize an integrated quantum memory architecture with defect centers in diamond. Building on the progress made with NV and SnV centers, the aim is to develop coherent control, improved spin-photon interfaces, and deterministic phase gates in order to store photonic time-bin qubits and retrieve them flexibly. This will be supplemented by the development of sources based on the same defect centers and the integration of fast photonic switches. This will create the components for a demonstrator that implements the functionality of an on-demand quantum memory.

The HUB-Theo subproject addresses the theoretical advancement of integrated quantum registers from SnV centers in photonic integrated circuits. The focus is on maintaining coherence and developing fault-tolerant architectures. For this purpose, machine learning methods – in particular LSTM networks and transformers – are used to model spectral fluctuations and derive correction strategies, as well as to optimize emitter properties and fabrication processes.

In addition, phononic modes in nanostructures and their influence on coherence are investigated, error correction methods for integrated registers are developed, and concepts for quantum physically unclonable functions (QPUFs) with color centers in diamond are tested.