- Quantum Science and Technology
- Photonics, Lasers and Nonlinear Optics

Wavefunction of an exciton-polariton condensate trapped in an optically-induced chaotic billiard potential. This system was used in our lab to demonstrate the non-Hermitian properties of polariton condensates [Gao et al., Nature 526, 554 (2015)]

Exciton polaritons are bosonic composite particles that are part light and part matter. They are composed of photons and excitons (electron/hole pairs) forming in semiconductor microcavities in the strong light-matter interaction regime. Akin to ultracold neutral bosonic atoms, polaritons can undergo Bose-Einstein condensation. In a **Bose-Einstein condensate** (BEC), millions of bosons occupy a single quantum mechanical state and display collective quantum behaviour, thus bringing the quantum physics onto the macroscopic scale. As one of the most sensitive and controllable quantum systems, a BEC has applications ranging from precision measurement sensors and metrology standards, through to tests of the fundamentals of quantum mechanics.

The **exciton-polariton BEC** has many similarities with the BEC of neutral atoms, but can be obtained at both cryogenic and room temperatures in a solid state. Observation of the first exciton-polariton BEC in 2006 has prompted the emergence of **polaritonics** – a new field of optoelectronics that employs collective quantum effects in solid state, cost-effective devices.

The ANU Polariton BEC group and laboratory conducts both experimental and theoretical studies of fundamental properties of exciton-polariton condensates and their manipulation by structured pumping and external potentials. Students joining the group can be involved in the following lines of investigation:

- Non-Hermitian quantum physics of exciton-polaritons
- Ultrafast transient dynamics of spontaneous condensation
- Exciton-polarioton condensatiion in periodic "superlattices"
- Strong light-matter coupling in novel atomically thin materials

Students interested in either theory or experiment are encouraged to apply.

This research project can be tailored to suit students of the following type(s)

- Honours or MSc project
- Phd or MPhil