Arxiv: Certifying high-dimensional quantum channels

Annameng Ma

We are excited to announce our latest arXiv submission: “Certifying high-dimensional quantum channels” (https://arxiv.org/abs/2408.15880). High-dimensional quantum communication offers significant advantages like increased information capacity and enhanced noise resilience. But how do we reliably certify that a quantum channel can transmit this high-dimensional information?

In our paper, we introduce novel, efficient methods for characterizing the dimensionality of quantum channels. Using a prepare-and-measure setup, we develop certification witnesses for both fully and partially trusted scenarios. We apply these methods to a photonic experiment, successfully certifying dimensionalities up to 59 through a commercial graded-index multi-mode optical fiber. Additionally, we provide detailed numerical simulations that model the noise behaviour of the fiber and explore more advanced certification techniques.

We developed witnesses for an unknown high-dimensional quantum channel Λ with: a) a fully trusted receiver’s device, and b) a partially trusted model.

Our work represents a key step towards robust, high-dimensional quantum communication systems. For more information, check out our full preprint!

BBQLab @ Quantum 2.0

mehulmalik

The BBQLab team had the pleasure of attending the Optica (OSA) conference Quantum 2.0 in Rotterdam, NL this June. We presented 4 talks and 2 posters from our group, and heard some fantastic presentations and tutorials on the frontier of quantum technology research. It was a very nice event that seamlessly brought together academia and industry in the cool city of Rotterdam (which even boasts a neighbourhood called the Cool district!)

Sophie @ Emergence of classicality, Dublin

willmccutcheon

Sophie went to Dublin’s Trinity College on monday (15-19th July) to attend and present at The Templeton foundation’s international conference “Emergence of Classicality: New Perspectives on Measurements in Quantum Theory” (EoC24) bringing together leading experts on topics in the foundation of quantum physics. Joining an esteemed program of speakers she followed Jaroslaw Korbicz to present “Equilibration of objective observables in a dynamical model of quantum measurements” (https://arxiv.org/abs/2403.18016).

The conference is devoted to quantum measurement, quantum paradoxes, the emergence of classicality and objectivity, quantum thermodynamics, equilibrium of closed systems and experiments. Alongside pontificating on foundational questions of QM they enjoyed some local culture and joined a Cèilidh….all together now… join hands, swing across in a star, face partners, set twice. Spin partners and dance a grand chain round…. 2, 3, 4… and from the top…

Welcome Samuel!

dylandanese

We warmly welcome Samuel Donachie. Arriving from Paris, France, where he’s currently studying physics at the Sorbonne University, Samuel is here to stay with us for his Masters internship.

His scientific interest lies in exploring quantum information on the platform of optics. Outside of studies and physics he enjoys getting exercise with gymnastics and climbing, playing video games, and reading fantasy novels.

Let’s make this stay memorable!

Congrats Sophie and Mariana!

mehulmalik

Last week was a big one for BBQLab with our PhD students Sophie and Mariana both winning poster prizes at two different conferences across the UK!

Sophie won the runner’s up best poster award at the Bristol Quantum Information Technologies Workshop (BQIT:24) for her poster on “Certifying the dimensionality of a quantum channel” and Mariana won the best poster award at the Scottish Conference in Optical Technologies (SCOT) for her poster on “A multiplexed programmable quantum photonic network.” Mehul also had the privilege of giving a keynote talk at the SCOT conference, which brought together the optics and photonics community in Scotland.

Congratulations both!