Alice, one of the three nodes of our quantum network. Inside the black aluminium cylinder, the diamond sample is cooled to -270 °C, to reduce the noise from the environment and enable the quantum control. Credit: Marieke de Lorijn for QuTech.

Researchers work on one of the quantum network nodes, where mirrors and filters guide the laser beams to the diamond chip. Credit: Marieke de Lorijn for QuTech.

Matteo Pompili (left) and Sophie Hermans (right), two of the coauthors of the research and PhD students in the group of Ronald Hanson, at one of the quantum network nodes. Credit: Marieke de Lorijn for QuTech.

Using a forest of optical components, laser beams of various colours and intensities are combined before being delivered to the diamond chip. Credit: Marieke de Lorijn for QuTech.

High-speed classical communication and control electronics is needed to establish quantum entanglement across the quantum network. Credit: Marieke de Lorijn for QuTech.

The diamond chip of the middle node of the quantum network – Bob – is installed in a cryogenic confocal microscope. At the centre, it is possible to see the printed circuit board that is used to deliver electrical signals to the qubits. On the left, permanent magnets are carefully positioned to align the magnetic field. Credit: QuTech.

Artist’s impression of our three-node quantum network. The quantum bits are housed in a small piece of diamond which is mounted on a PCB (printed circuit board) to deliver electrical signals. Laser beams enable the control and readout of quantum information. The blue lines represent entanglement across the nodes. Credit: Scixel for QuTech.