Robust entangled state preparation in lossy cavities

During my doctoral research I worked on various theoretical frameworks for entagled state preparation, including entangled pair generation1 and the generalisation to cluster state build-up2.

The problem being addressed was that while entangled state generation is theoretically straight-forward in closed systems (isolated from the surrounding environment), this idealised setup is impossible to achieve in real-world settings. Consequently, the coupling to the environtment tends to introduce loss of coherence, prohibiting scalability of entangled quantum states needed to attain quantum computing.

Most approaches to this problem look at ways to better isolate the system from the environment. Here, on the other hand we examined if we could utilize the very decoherence mechanisms causing the problems, to attain entangled state preparation.

Through theoretical calculation and computational simulation, we were able to show that indeed entangled state preparation is possible, by using measurements on the system, or Quantum Jumps.


Analysis of frequency mismatch on optical quantum information processing

Many Quantum Information Processing (QIP) schemes rely on few-photon interference effects. However, these treat photons as indistinguishable particles, something that is rarely the case in real-world scenarions. This can be due to slight differences in their frequencies.

Together with Dr Sean Barrett, I analysed and wrote simulations of the effect of this frequency mismatch, and we were able to draw critical insights into the impact on optical QIP schemes3.