arXiv: Entangled ripples and twists!

Artist’s depiction of entangled Laguerre-Gaussian modes in 43 dimensions

In a recent preprint on arXiv, we demonstrate the full-field entanglement of radial (ripples) and azimuthal (twists) Laguerre-Gaussian modes of light. While the azimuthal degree-of-freedom has attracted a lot of interest over the past two decades, the radial degree-of-freedom presents some unique challenges to experimentalists.

By carefully tuning our optical system parameters and adopting some recently developed techniques for precise spatial mode measurement, we generated and measured entanglement in a 43-dimensional radial and azimuthal LG mode space. We also studied two-photon quantum correlations between 9 LG mode groups, which are of significant interest in the field of fibre optics.

Check out the preprint here: https://arxiv.org/abs/2104.04506

npj Quantum Info: Flexible semi-device-independent randomness

A European 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 on AVS Quantum Science, and is now in the cover of the journal’s first issue of 2021!

Working in collaboration with the HWQuantum group, here at Heriot-Watt University, we show that the noise tolerance of high-dimensional entanglement can be significantly enhanced. While answering the question of “Is high-dimensional photonic entanglement robust to noise? involves the complex interplay between the characteristics of the state, the channel, and the detection system, we provide easily measurable experimental parameters that accurately predict system performance and noise bounds, so 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.

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!

BBQ Lab @ Q-Turn 2020

This week we are attending Q-Turn 2020, an international quantum information workshop series being held virtually this year. I have also had the honour of serving as programme committee chair for this very exciting event!

In addition to showcasing cutting-edge scientific research on all things quantum, Q-Turn 2020 has an awareness programme focussing on a wide range of issues such as mental health and harassment in academia.

Our group will be represented by Vatshal and Natalia, who are presenting a talk and a poster respectively on some of our recent work. We hope to see you there!

Here is a nice video summary of Natalia’s poster: