Michael Philipp Adams, Doctoral researcher in nanomagnetism at the University of Luxembourg, has investigated the behaviour of three cylindrical magnets. His findings has been published in the American Journal of Physics as a single author. It will help physics teachers to explain the theoretical and experimental basis of different magnet arrangements,
In the paper entitled “Understanding two-dimensional tractor magnets: theory and realizations“, Michael Philipp Adams from the Department of Physics and Materials Science presents a comparative theoretical and experimental investigation of two-dimensional tractor magnet configurations. The minimal tractor magnet consists of a rigid assembly of one attracting magnet (attractor), two repelling magnets (repulsors), and a fourth magnet (follower) that is magnetically stabilized in a local energy minimum.
“The theoretical framework relies on magnetostatics and stability analysis of stationary equilibria. To calculate the magnetostatic force and energy, we use a multipole method. In a first approximation, we derive analytical results from the point dipole approximation. The point dipole analysis defines an upper bound criterion for the magnetic moment ratio and provides analytical expressions for stability bounds in relation to geometry parameters. Our experimental results are consistent with the predictions from the fourth-order multipole expansion. Beyond the minimal tractor magnet, we introduce a more advanced configuration that allows for a higher magnetic binding energy and follower capture at larger distances”, explains Michael.
With this publication, college and university physics teachers will find the theoretical basis for this curious stability, a thorough experimental analysis of the stability of different possible magnet arrangements, and supplemental videos and 3D printing plans so they can create and study their own tractor magnets with their students.”
‟ Michael carried out this project completely independent and it was accepted for publication in the American Journal of Physics, an internationally renowned university journal. This is a remarkable achievement.”

Professor and PhD supervisor