Where Monopoles Live (IMAGE) Joint Quantum Institute Caption The unit cell for "spin ice" materials consists of two tetrahedrons. The arrows show the orientation of the magnetic atoms within the material Credit Stephen Powell Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.