van der Waals (vdW) materials are ideal platforms to host light at the nanoscale (nanolight) with unprecedented properties such as strong in-plane anisotropy, arbitrarily large momenta and high density of optical states, opening the door to develop planar optical nanodevices compatible with current on-chip technologies. Remarkably, the in-plane anisotropic propagation of nanolight can be steered by stacking two slabs of a vdW material rotated with respect to each other, resulting, for example, in canalization along one specific direction. Inspired by this breakthrough in nano-optics, which extends the exciting prospects of twistronics to the optics realm, this ERC project aims to develop the field of Twistoptics, where stacks of twisted layers of vdW materials enable unprecedented active control of light and light-matter interactions at the nanoscale. In a first stage, we will carry out a study of the most fundamental optical phenomena in Twistoptics - reflection and refraction of nanolight in twisted vdW structures-, and develop a technological platform that will enable active manipulation of nanolight via strain fields. In a second stage, we will make use of this knowledge and technological capabilities to design and fabricate functional nanodevices to explore directional strong coupling between nanolight and molecular vibrations, as well as inter-subband transitions in 2D semiconductors -in order to develop quantum Twistoptics. This proposal envisions the modification of material properties and dynamics at the nanoscale and the realization of efficient and compact sources of IR radiation and polaritons working at room temperature. These fundamental scientific advances will be of enormous relevance for the development of new nanotechnologies that will have a broad impact in various fields, such as molecular nano-sensing, quantum nanosciences, or nano-chemistry, where active control of fundamental light-matter processes at the nanoscale is of vital importance.
