Applied Physics/Physics Colloquium: Exciton-Polariton based Photonic Circuits

Topic: 
Exciton-Polariton based Photonic Circuits
Wednesday, February 25, 2015 - 2:00pm to 3:00pm
Venue: 
Spilker 232
Speaker: 
T. C. H. Liew (Nanyang Technological University)
Abstract / Description: 

Exciton-Polaritons in semiconductor microcavities are hybrid states of light and matter exhibiting a mix of electronic and photonic properties [1], including strong nonlinearity, low dephasing, ultrafast dynamics, sensitivity to electric and magnetic fields and a rich spin dynamics. These properties are ideal for the construction of a new generation of polaritonic information processing devices, such as exciton-polariton based circuits [2].

For such applications, attention is needed to overcome disorder in the system. Here, advances in the patterning of polariton potentials [3] are theoretically expected to allow for topological polaritons [4]. In analogy to photonic topological insulators [5], propagation immune to scattering with disorder is predicted.

In this presentation, I will also show preliminary work in the application of exciton-polaritons in unconventional circuit architectures such as neural networks [6].

Finally, I will consider the enhancement of nonlinear polaritonic effects at the quantum level with a viewpoint toward triggered single-photon emission [7].

Dr. Liew received his PhD from the University of Southampton (UK) in 2008 and completed postdoctoral research at the National University of Singapore and Ecole Polytechnique Federale de Lausanne (Switzerland). He made several contributions to the theory of light-matter coupled systems, having predicted fundamental effects, such as the unconventional quantum blockade and exciton-polariton spin-to-orbital angular momentum conversion, and described several experimental results, such as the optical spin Hall effect and various spin switches. In 2013 he received the Lee Kuan Yew Fellowship at Nanyang Technological University, where he has focused on the theoretical development of photonic applications in hybrid systems: terahertz frequency sources, quantum light sources, and photonic circuits.