Logic Masters Deutschland e.V.

Click on the puzzle image to play!

Rules: Normal Sudoku rules apply. A domino is a pair of cells that share an edge; its “orientation” is the direction from the larger to the smaller digit, and its “magnetic moment” their difference. Each cage is a “magnetic domain” that must be filled completely with nonoverlapping dominos whose orientations and magnetic moments are the same; the magnetic moments must agree with the cage clue if given.

Please leave a comment if you like it!

Example: The following image provides a fully solved example on a 4x4 grid. You may solve the example for yourself by clicking on the image.

Background: Ferromagnetism is responsible for many everyday phenomena and is used in technological applications ranging from electric motors to data storage in hard drives. A ferromagnet is typically divided into small magnetic domains (“Weiss domains”) such that in each domain, the elementary magnetic moments (resulting from spins) are oriented in the same direction, but those orientation directions can differ between domains, just like in the puzzle rules. If the domain orientations and domain sizes are distributed statistically, no total macroscopic field results. However, with a strong enough external field, the domain walls can be moved and spins flipped, possibly creating a permanent magnet (“remanence”).