Liew Seminar Abstract Feb 24

Applications of exciton-polaritons in hybrid light-matter coupled systems

see more polished abstract here

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 have led to the study of a number of fundamental effects, namely: Bose-Einstein condensation, the optical spin Hall effect, bistability, and pattern formation. The mixed properties of exciton-polaritons are also promising for the construction of a new generation of polaritonic devices. In this presentation I will review recent theoretical developments in this field and highlight future directions open for further research. In particular, I will focus on optical circuits, quantum light-sources and terahertz frequency sources. Optical circuits require special attention to overcome dissipation and disorder in the system. A complete theoretical architecture of polaritonic circuits has been constructed based on a mechanism of bistability [2], while mechanisms of topological polaritons [3], immune to scattering with disorder, have been identified. Neural network architectures will also be discussed [4]. For quantum light-sources, such as single-photon sources, exciton-polaritons were for a long time considered unpromising due to their strong dissipation that exceeds nonlinear interaction strengths. However, an unconventional blockade mechanism based on quantum interference circumvents this problem in coupled mode systems [5]. Systems with nonlinear interactions between modes are predicted to allow for triggered single photon generation [6]. Finally, the efficiency of terahertz radiation generation will be considered in the framework of a bosonic cascade, where an optical photon generates multiple terahertz photons [7].

References

[1] I Carusotto & C Ciuti, Rev. Mod. Phys., 85, 299 (2013).

[2] T Espinosa-Ortega & T C H Liew, Phys. Rev. B, 87, 195305 (2013).

[3] C-E Bardyn, T Karzig, G Refael, & T C H Liew, arXiv:1409.8282 (2014).

[4] T Espinosa-Ortega & T C H Liew, accepted for publication in Phys. Rev. Lett. (2015).

[5] T C H Liew & V Savona, Phys. Rev. Lett., 104, 183601 (2010).

[6] O Kyriienko & T C H Liew, Phys. Rev. A, 90, 063805 (2014).

[7] T C H Liew, et al., Phys. Rev. Lett., 110, 047402 (2013).