PRL: Genuine High-Dimensional Quantum Steering

Theory and experiment coming together to demonstrate genuine high-dimensional quantum steering.

Our new paper “Genuine High-Dimensional Quantum Steering” has been published in Physical Review Letters. Collaborating along with the Quantum Information Theory Group at the University of Geneva, we formulated simple two-setting steering inequalities, the violation of which certifies a lower bound on the dimension of entanglement in a one-sided device-independent setting.

We experimentally certified 15-dimensional steering in dimension d = 31. It is the highest dimension of entanglement ever certified in a one-sided device-independent setting, which unlocks the potential of high-dimensional entanglement in several applications such as semi-device-independent quantum information protocols. More generally, this represents an important step towards the realization of noise-robust, high-capacity quantum networks in the near future.

npj Quantum Info: Flexible semi-device-independent randomness

A Europe-wide collaboration: With colleagues in Czech Republic, Slovakia, Austria, Poland and Spain, theory and experiment came together for the development of a quantum random number generation framework that can be applied in a wide range of physical scenarios.

Our new paper “Semi-device independent random number generation with flexible assumptions” has been published in npj Quantum Information. Working along with theorists all over Europe, we formulated a framework for semi-device-independent quantum random number generation, and demonstrated the protocol with an experiment in the BBQ Lab. Our approach works with flexible assumptions and different levels of trust, allowing it to be implemented over a large number of practical situations.

This work was the result of an international collaboration that involved people in 6 different countries. Even though some of the co-authors haven’t even met in person, we developed theoretical methods and showed their experimental realisation. This is the power of science: joining people together, even during these difficult times!

AVS Quantum Science: Enhancing noise tolerance with high-dimensional entanglement

Our article “Is high-dimensional photonic entanglement robust to noise?” was featured on the cover of AVS Quantum Science’s first issue of 2021

Our paper “Is high-dimensional photonic entanglement robust to noise?” has been published as a Featured Article in AVS Quantum Science, and is now on the cover of the journal’s first issue of 2021!

Working in collaboration with the HWQuantum group at Heriot-Watt University, we show that the noise tolerance of high-dimensional entanglement can be significantly enhanced. Answering the question “Is high-dimensional photonic entanglement robust to noise?” involves the complex interplay between the characteristics of the quantum state, the channel, and the detection system. In our work, we provide easily measurable experimental parameters that accurately predict system performance and noise bounds, so that the optimum entanglement measurement strategy can be chosen. This works demonstrates the potential of high-dimensional entangled states in the realisation of entanglement-based communication systems under extreme noise conditions.

For some media coverage of this work, please see this AIP Scilight article.

Welcome Suraj!

We are delighted to welcome our third PhD student Suraj Goel, who joins us from India!

Suraj has completed his B.Tech in Engineering Physics at the Indian Institute of Technology Delhi (IITD), where he has worked on structured light and quantum information. His enthusiasm towards physics and experience in electronics will be valuable to the group.

Welcome to the BBQ Lab, Suraj!

Quantum Journal: Pixel Entanglement

Twas the night before Christmas, when all through the lab,
Not a creature was stirring, not even a browser tab,
The laser was focused on the crystal with care,
In the hope that pixel entanglement soon would be there!

In our recent paper published in the journal Quantum, we demonstrate high-dimensional entanglement of “pixels” of light with a record dimensionality, quality, and measurement speed! We achieved entangled state fidelities of up to 94.4% in a 19-dimensional state-space, entanglement in up to 55 local dimensions, and an entanglement-of-formation of up to 4 ebits. We were also able to improve upon the time taken by previous techniques for measuring entanglement by more than two orders of magnitude! This work was done in collaboration with our friends in Vienna and the Czech Republic.