An efficient neutral atom quantum network node with a parabolic mirror*

Quantum networking is essential for enabling several quantum enhanced applications. These include modular and scalable quantum computing, secure data transmission, and distributed quantum sensing. A fundamental element of such a network is an atomic node capable of generating atom-photon entanglement at high fidelity and high rate.

 

Here, we report on our progress towards building and characterizing efficient network nodes based on parabolic mirrors and pre-aligned optics. Each node requires ten sets of optical trains for atom cooling, trapping, addressing, and photon collection. We have built eight of these optical trains from millimeter-size optics pre-aligned and glued on a Macor platform, all interfaced with optical fibers. This design opens the pathway towards a fully plug-and-play quantum repeater node that can be deployed in the field without misaligning the optics.

 

A parabolic mirror is used at each node to focus the dipole trap beam and to collect emitted photons, which are coupled into the same fiber via a shared lens. Since any slight misalignment shifts both the trap position and the collection path together, efficient photon collection is maintained. Preliminary results show high photon collection efficiency near theoretical limits.