Repulsive Polaron (IMAGE) University of Innsbruck Caption The potassium atom in the middle (blue) repulses the smaller lithium atoms (yellow). This creates a complex state, which can be described physically as a quasiparticle. In various ways it behaves like a new particle with modified properties. Credit Graphics: Harald Ritsch Usage Restrictions Only in connection with reports on research results of Rudolf Grimm et.al. 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.