Through a three-year, $550,000 grant, Mishkat Bhattacharya, a theoretical physicist at the Rochester Institute of Technology, is investigating new precision quantum sensing solutions for the U.S. Navy’s Office of Naval Research.

A continuation of a previous award, Bhattacharya will test interactions between light and matter at the nanoscale and analyze measurements of weak electromagnetic fields and gravitational forces. Specialized microscopes measure theoretical predictions that describe matter at the nanoscale in which a nanometer equals one-billionth of a meter and a human hair measures between 80,000 to 100,000 nm. Bhattacharya works in the field of levitated optomechanics, an area of physics that investigates nanoparticles by trapping them in a laser beam. Laser trapping – a method known as “optical tweezers” – tests the limits of quantum effects in isolation and eliminates physical disturbances from the surrounding environment. Using the techniques of laser trapping, Bhattacharya takes quantum mechanics to the next level by probing quantum effects in the nanoparticles, which contain billions of atoms. He investigates where quantum mechanics meets classical physics and explores light-matter interaction in macroscopic quantum physics.

His first study for the Office of Naval Research determined the smallest force that could be detected with a diamond crystal that levitated without spinning. The new project investigates the outcomes of three nanosystems, each using nanoparticles optically trapped under different conditions: A particle containing an impurity that acts as a spin sensitive to magnetic fields or as an excess charge sensitive to electric fields; a particle moving like a pendulum in three dimensions; a particle larger than the wavelength of light entrapping it.

“Levitated optomechanical systems provide a clean platform for studying quantum optics, information science, and precision measurement and sensing,” Bhattacharya said.