Atomic force microscopy is a powerful tool in characterizing surface topography at the nanoscale. A sharp needle, with a tip size as small as 10 nanometers, being thousands of times thinner than a hair, is used to gently "touch" the sample surface. Piconewton-level force can be picked up. When the sample is illuminated with light, selected properties related to the optical absorption can be probed by the needle. We are particularly interested in studying the certain types of molecules which bare three-dimensional asymmetry, namely chirality. To do so, we fabricate "snowflakes" with different chirality to form entanglement with the analyte molecules. In this way, properties related to the chirality of the specimen can be imaged at the nanoscale. We name this technique enantioselective optical force microscopy.
