Entanglement is one of the most counterintuitive phenomena in quantum physics. We study the physics of highly entangled photons in complex systems, and explore how they can be harnessed for novel quantum technologies. 

Scattering of entangled photons

Entanglement plays a key role both in fundamental research of quantum physics and in applications in quantum information theory. In our research, we study the physics of highly entangled photons in complex photonic systems such as random media. On the fundamental level, we study interesting coherent phenomena exhibited by entangled photons in scattering media, such as two-photon speckle patterns and enhanced back scattering of single and entangled photons. In many cases, our deep understanding of the physics of such systems is later utilized for new applications related to quantum technologies. 

Controlling high dimensional quantum bits

High dimensional quantum bits (coined qudits) are gaining increasing popularity as a platform for quantum communications due to their improved security, enhanced resilience to noise and increased capacity compared to traditional two-dimensional qubits. Unfortunately, high dimensional entangled states are highly fragile to the environment, making practical implementations challenging. To tackle this challenge, we develop novel methods to create tailored quantum states which are highly resilient to diffraction and scattering, such as entangled Airy photons. In addition, by utilizing unique properties of highly entangled photons, we extend wavefront shaping to the quantum domain and actively compensate for the scattering of spatially entangled photons in real-time. Following proof-of-concept demonstrations in the lab, we confirm the relevance of our findings using numerical simulations of real-world scenarios such as scattering by turbulent atmosphere in satellite-based quantum communications.

To achieve high-dimensional quantum communication without a line of sight, there is a growing effort to develop quantum communication protocols that are based on multimode fibers. We show that by spontaneous four-wave-mixing we can generate multimode photon-pairs in a multimode fiber and thus bypass the challenge of coupling high-dimensional photonic states into the fiber. We show the photons are correlated in the fiber mode basis using an all-fiber mode sorter.