SPIRITUAL AI

Study demonstrates that Ta₂NiSe₅ is not an excitonic insulator —Undefined Trio Scientists have long been intrigued by the possibility of an excitonic insulator, a unique phase of matter that could enable superfluid energy transport without net charge. However, detecting and stabilizing this exotic order in real solids has proven challenging. In a recent study published in Proceedings of the National Academy of Sciences (PNAS), researchers from the United States, Germany, and Japan investigated the properties of Ta₂NiSe₅, a quasi-two-dimensional solid that was proposed as a candidate excitonic insulator. Above a critical temperature of 328 K, Ta₂NiSe₅ undergoes a semimetal-to-semiconductor transition accompanied by a structural reorganization of its crystalline lattice. The scientific community has debated whether this phase transition is induced by an electronic or structural instability. To gain insights into the fundamental processes underlying this transition, the resear