Researchers at the Indian Institute of Technology Guwahati and USA’s Columbia University have unveiled a groundbreaking method for nanopatterning using a simple tabletop IR laser. IIT Guwahati Physics Department’s Assistant Professor Dr Rishi Maiti and a former post-doctoral scientist from Alexander Gaeta’s quantum and non-linear photonics group has detailed the findings of this research in the esteemed journal Science Advances.
Nanopatterning, the process of creating patterns on materials at the nanometre scale, plays a pivotal role in various technological applications, including advanced light detectors, solar cells, lasers, and light-emitting diodes. Traditional methods of nano patterning typically require specialised equipment and infrastructure, making them inaccessible and costly.
Seeking a more accessible and cost-effective alternative, the multi-institutional team turned to a technique called “optical driving,” leveraging the resonance frequency principle in materials. Through this innovative approach, termed “unzipping,” researchers successfully cleaved hexagonal boron nitride using an infrared laser, resulting in atomically sharp lines across the sample, measuring just a few nanometres in width.
The utilisation of laser wavelengths at 7.3 micrometres facilitated clean lattice breaks, yielding controllable nanostructures. By “unzipping” two parallel lines, researchers created a nano-dimensional cavity capable of trapping phonon-polaritons, unique quasi-particles formed from the interaction of light and vibrations. These trapped particles hold promise for highly sensitive mid-infrared sensing and spectroscopy applications.
Dr Rishi Maiti, co-author of the study, highlighted the significance of this breakthrough, stating, “This novel nano-patterning technique using optically induced strain opens doors to a myriad of possibilities in nanoscience and technology. Its simplicity and effectiveness mark a significant advancement in the field, with far-reaching implications across various industries.”
Dr Maiti envisions diverse applications for this breakthrough, including designing hard masks for electrode fabrication on 2D materials and forming twisted hetero structures for quantum technologies. This development heralds a new era of accessible and cost-effective nano patterning techniques, with potential applications spanning a wide range of industries.
