The Bhattacharya group is broadly interested in light-matter interactions from the perspective of fundamental science as well as technological applications. Currently it is focused on the interplay of electromagnetic modes of radiation, such as laser light, with nanofabricated components, such as mechanical oscillators and rotors. Major aims are the cooling of macroscopic objects into the quantum regime and establishing the limits to quantum sensing of mechanical displacement, force, and rotation, for example. These investigations are expected to test the foundation of quantum mechanics as well as to yield next generation sensors that circumvent the limits posed by quantum mechanics to their sensitivity. Some of the group effort also goes towards investigating other related platforms for quantum technologies such as ultracold atoms and molecules. The work is fully theoretical, involving mostly analytical calculations, using the techniques of quantum optics and atomic physics, and some medium-scale numerical work. Close collaborations exist with experimental groups locally, nationally, as well as internationally. The program involves researchers at every level, including undergraduate, masters, and doctoral students as well as postdoctoral scholars. Recent funding sources include the Research Corporation for Science Advancement, the Office of Naval Research, and the National Science Foundation.