Physicists at the University of Vienna have watched gramicidin, a natural antibiotic made up of 15 amino acids, interfere with itself, in an experiment that paves the way for a new era of quantum biology.
Their approach is to create a beam of ultra-cold gramicidin molecules and then to measure the interference pattern created when this beam interferes with itself. The gramicidin molecules have been swept up in a beam of argon atoms travelling at 600 meters per second. In this beam, the gramicidin has a wavelength of 350 femtometers. The wavelength of the beam is about a thousandth that of the biomolecules themselves. The team use an extraordinarily sensitive technique known as Talbot-Lau interferometry to measure the size of the interference pattern.
The results were persuasive: the molecular coherence had been delocalized over more than 20 times the molecular size which would be impossible if the gramicidin molecules were pure particles. It is possible only with wavelike interference. (MIT & arXiv)