Welcome to the qram lab!

The long-term vision of the qram lab, led by Dr. Mikael Afzelius, is to develop a quantum repeater for long-distance quantum communication, based on spin-photon entanglement, quantum memories and teleportation of entanglement. To this end we explore rare-earth doped crystals, a leading solid-state candidate for quantum repeaters.

Our work is highly interdisciplinary as it covers fundamental material properties, coherent spectroscopy, quantum optics, and quantum memories. We strive to bring all this together in demonstrations of basic quantum repeater functionalities.

Research Themes

Quantum Memories

Quantum Photonics

Optical and Spin Spectroscopy

News (archive)

Optical light storage in 171Yb3+:YSO exceeding 1 ms

Frebruary, 2020

Our recent publication in PRL shows for the first time a storage of light in a nuclear-spin hybrid system using the AFC memory protocol.

This work further highlights the capabilities of Yb as a quantum memory and is a big steping stone towards the implementation of this new material into a global quantum network.

171Yb3+:YSO - The quantum memory of tomorrow

July, 2018

Our new Paper about the study of optical and spin coherence times in a new solid state material (171Yb3+:YSO crystal) containing electronic spins, was published in Nature Materials.

This material opens up a new field of possibilities for creating a global quantum network; it also underlines the importance of pursuing fundamental research in parallel with more applied research, such as devising a quantum memory.

Efficient optical pumping using hyperfine levels in 145Nd3+:YSO

May, 2018

Tradidionally in the rare-earth community is believed that Kramers ion-doped solids experience limited storage efficiency compared to non-Kramers. In our recent paper, published in NJP, we study the relaxation processes limiting optical pumping and achieve efficiencies comparable with state of the art non-Kramers quantum memories.