Superfluid effects in defocusing nematic liquid crystals
The last years saw the emergence of nonlinear optical materials, with local and nonlocal nonlinearities, as experimentally accessible systems to implement optical analogues of quantum fluids. In these systems, a light beam propagating in the nonlinear medium can be interpreted as a fluid, where the diffraction in the transverse plane to the propagation gives the effective mass of the fluid and the medium nonlinearity mediates the required interactions between the photons. This fluid interpretation and its application have been extensively studied, from the creation of superfluid-like flows and the study of phenomena associated with this effect to the implementation of gravity analogues. Furthermore, many optical materials have been considered, with a special interest in the ones that offer tunable mechanisms that allow to easily control the system properties to better explore and emulate the different phenomena. Recently, nematic liquid crystals have been proposed as an interesting tunable material capable of supporting superfluids of light. These systems have a nonlocal character and offer external mechanisms that can be used to tailor the nonlinearity to better emulate the desired analogue system. Indeed, through the application of an external electric field perpendicular to the direction of propagation, is it possible to control the nonlocal length of the nonlinearity. This mechanism offers interesting opportunities in the present context. In this work, through numerical methods based on GPGPU supercomputing, we explore the possibility of observing superfluid effects in defocusing nematic liquid crystals. In particular, we explore the possibility of observing the drag force cancelation and the emission of quantized vortices, which are two manifestations of a superfluid flow. Furthermore, we also discuss the possibility of using these systems for creating an analogue of quantum turbulence with these materials. These studies constitute a stepping-stone towards the implementation of gravity analogues with nematic liquid crystals.
Univ. do Porto (Portugal), INESC-TEC (Portugal)
I received my master's degree in physical engineering from the University of Porto, Portugal, in 2018. After, I worked as a Research Assistant in the Centre for Applied Photonics, INESC TEC Porto, Portugal for 11 months. Currently, I am doing my Ph.D. also at INESC TEC in collaboration with the University of Glasgow in the field of quantum optical many-body systems and optical analogues. I am the author of 2 journal publications and several communications in international conferences, and in 2017 I won one national scientific prize. My main scientific areas are quantum and nonlinear optics and high-performance computing with GPU-accelerated physical simulations.