The QUANT-NET Testbed Development and Preliminary Results

The U.S. Department of Energy (DOE) is currently supporting Berkeley Lab (LBNL), UC Berkeley (UCB), Caltech, and the University of Innsbruck in constructing a testbed for quantum networking technologies (QUANT-NET). The goal is to establish this network between two sites, LBNL and UCB, connected with an entanglement swapping substrate over ~5 km optical fiber and managed by a quantum network protocol stack. On top of this entanglement swapping substrate the research team will implement the most basic building blocks of distributed quantum computing and quantum repeaters by teleporting a controlled-NOT gate between two far trapped-ion quantum computation nodes. This paper presents QUANT-NET, its design, key technologies, and preliminary results. The preliminary results are focused on the QUANT-NET testbed infrastructure control, measurement, and characterization, which includes the implementation of a Hong-Ou-Mandel (HOM) interferometer across the fiber links, and the development and deployment of link polarization drift control in the testbed. These implementations are critical to our next stage research activities.