“Physicists have long predicted the possibility of tying knots in quantum fields. But no one has been able to make or observe a three-dimensional quantum knot, until now. In a breakthrough discovery explored in a paper published in Nature Physics, one of the most prestigious journals in physics, a scientific team led by Amherst Physics Professor David S. Hall ‘91 and Aalto University (Finland) Professor Mikko Möttönen have found a way to create knotted solitary waves in a quantum-mechanical field. The discovery builds on their recent work on Dirac monopoles and isolated monopoles, and is yet another extraordinary step forward in understanding the nature of quantum fluids. The isolated monopole research in particular, Hall says, led to the quantum knot discovery.”