The researcher worked at the Center for Nanosciences and Nanotechnologies (C2N), CNRS, in close collaboration with Prof. Jacqueline Bloch and Dr. Alberto Amo.
The researcher began the project with a theoretical investigation of nonlinear physics of two coupled resonators. The researcher discovered that, due to the nonlinearity, this system supports multiple steady-states. He predicted that one of these states could enable a novel type of control of the phase that polaritons pick when hopping between coupled cavities. Based on his predictions, the researcher performed numerous experiments with coupled semiconductor microcavities in highly nonlinear regimes. For this purpose, he used the technological infrastructure and samples available at C2N. Indeed, the researcher experimentally observed multiple steady-states at a given driving condition, i.e. multistability. Through interferometry measurements, the predicted nonlinear optical phase control was evidenced. This phase control opens the way to the implementation of artificial gauge fields for light. These results led to a high-impact publication in the journal Nature Communications [S.R.K. Rodriguez et al, Nature Commun. 7, 11887 (2016)]. The results were also disseminated in many international conferences, invited talks, workshops, and seminars, in Europe, USA, Japan, and Mexico.
Towards the end of the second year, efforts shifted towards observing quantum effects with polaritons. This project was performed in close collaboration with the theory group of Prof. Cristiano Ciuti in Paris. For the experiments, the researcher built a new setup at C2N, and he developed a novel protocol to experimentally investigate the influence of quantum fluctuations on the polariton dynamics. The experiments consisted of scanning the driving power up and down at various speeds, and measuring the dynamical optical hysteresis of the microcavity. Due to the influence of quantum fluctuations, the hysteresis area decayed following a double power law as a function of the scanning time. This result was found to be in agreement with recent theoretical predictions from the group of Prof. Cristianio Ciuti. The critical time at which the hysteresis area transitioned from one power law to another was also found to be highly sensitive to the intrinsic polariton-polariton interaction strength. This effect is not captured by the mean-field approximation, and therefore constitutes a remarkable discovery in the field. Furthermore, by investigating cavities with different interaction strengths, signatures of a dissipative phase transition of light were obtained. These results led to a high-impact publication in the journal Physical Review Letters [S.R.K. Rodriguez et al. Phys. Rev. Lett. 118, 247402 (2017)]. These results have also been presented in numerous contributed and invited talks, seminars, and workshops, throughout Europe, USA, Mexico, and Japan.
From a career development point of view, the results of this action enabled the insertion of the researcher into a new scientific community for him. To this end, the transfer of invited talks by Jacqueline Bloch was also helpful.
