Motivated by experiments on a compound made of uranium, ruthenium and silicon, a team of theorists at Rutgers University predicts a new kind of magnetic order distinct from that found in ordinary magnets and antimagnets. The research explains a mystery spanning some 30 years. It also provides theoretical insight into how two kinds of electrons, one moving and the other localized around atomic sites, can mix quantum mechanically to lead to electronic states in which electrons organize themselves in unanticipated ways.

The discovery of new states of electronic matter and insights into the physical mechanisms that create them contributes to the knowledge base for electronic device innovations and future electronic device technologies.

The Rutgers team proposes a new kind of magnetism that is consistent with all known experimental data but it has an unusual hallmark. In an ordinary magnet, reversing time twice returns the magnetic order to its original state. Not so for hastatic order, which derives from the Latin word for spear. In this case, reversing time twice reveals the new state. This strange property of double time reversal is intimately connected to a fundamental quantum mechanical quality of the microscopic origins of hastatic order. The hastatic state is a refreshing idea that requires further experimentation. Whether or not this is the ultimate explanation for "hidden order," it is a new kind of magnetic order that may be reflected in puzzling behavior exhibited by a variety of materials.

The research was published in Nature.