ERC Starting Grant: PIQUaNT

We are happy to share that Mehul has been awarded an ERC Starting Grant by the European Research Council! The PIQUaNT project (Photonics for High-Dimensional Quantum Networking) will focus on technologies for the manipulation and control of structured light in space and time, with an emphasis on entanglement-based applications. We will soon be advertising PhD and postdoc positions for this project, so please keep an eye out. For more, please read the Heriot-Watt press release.

BBQ Lab @ Photon 2020

We are presenting five talks at Photon 2020, a biannual conference on photonics that is being held online this year. The registration is free for students, and we would be very happy if you tuned in! The talk schedule is as follows:

Tuesday, 11:30 AM
Saroch Leedumrongwatthanakun
Reconfigurable high-dimensional quantum gates using a multi-mode fiber

Tuesday, 2:45 PM
Vatshal Srivastav
Experimental Demonstration of High-Dimensional Steering

Tuesday, 3:00 PM
Will McCutcheon
Compressive Sensing of Dispersive Scrambling Channels

Wednesday, 3:45 PM
Mehul Malik
Unscrambling Entanglement through a Complex Medium

Thursday, 10:00 AM
Natalia Herrera Valencia
High-Dimensional Pixel Entanglement: Efficient Generation and Certification

Nature Physics: Unscrambling Entanglement

A chaotic speckle pattern that results from light being scrambled by a complex medium such as a multimode optical fibre. (Image credit: M. Malik and S. Goel)

In new work from our lab published in the journal Nature Physics, we demonstrate how high-dimensional entanglement can be transported through a complex medium consisting of a commercial multi-mode fibre supporting hundreds of spatial modes. This work was done in collaboration with Dr. Hugo Defienne from University of Glasgow.

In a quantum twist, the transmission matrix of the fibre was measured by mapping the entire matrix onto a single entangled state, which is an example of state-channel duality in quantum mechanics. Furthermore, the entanglement was regained without ever manipulating the fibre or the photon that entered it. Instead, we carefully scrambled the entangled partner that remained outside, allowing us to transport 6-dimensional entanglement through the fibre!

Popular media coverage: BBC News, Physics World, Physics Today, Heriot-Watt press release

N. H. Valencia, S. Goel, W. McCutcheon, H. Defienne, & M. Malik, Unscrambling Entanglement through a Complex Medium, Nature Physics (2020), doi: 10.1038/s41567-020-0970-1.

arXiv: Pixel Entanglement in 55 dimensions!

A 97-dimensional pixel hologram used in the experiment and two-photon correlation data

In a record-breaking result from our lab, we recently demonstrated the generation and certification of photonic high-dimensional entanglement with the highest quality, fastest measurement speed, largest dimensionality, and the most “entangled bits” of information till date!

We achieved this through several breakthroughs in theory and experiment, including a cleverly designed spatial-mode basis of macro-pixels and an efficient entanglement witness developed in collaboration with our colleagues in Austria and the Czech Republic. This result demonstrates that high-dimensional entanglement can indeed break out of the confines of an optical laboratory and enable practical, high-capacity quantum communication networks in the near future.

Preprint: N. H. Valencia,  V. Srivastav, M. Pivoluska, M. Huber, N. Friis, W. McCutcheon, and M. Malik, “High-Dimensional Pixel Entanglement: Efficient Generation and Certification,” arXiv:2004.04994 (2020).