Heating usually melts solids, but in the quantum world, an interesting phenomenon called supersolidity can occur. A collaborative effort between Francesca Ferlaino’s experimental team in Innsbruck, Austria, and Thomas Pohl’s theoretical team in Aarhus, Denmark, has shed light on the formation of supersolid structures through heating. These structures possess properties of both solids and superfluids, and this research provides a pioneering phase diagram for a supersolid at finite temperature.
Supersolids have emerged as a captivating field of study. In 2019, three research groups, including Francesca Ferlaino’s team at the University of Innsbruck, succeeded in definitively demonstrating this state in ultracold quantum gases. The subsequent work of Ferlaino’s team in 2021 focused on understanding the life cycle of supersolid states in a dysprosium atom dipolar gas. Surprisingly, they discovered that increasing the temperature actually promotes the formation of supersolid structures. Claudia Politi, a member of Ferlaino’s team, explained that this unexpected behavior stimulated theoretical advances, as previous research had paid little attention to thermal fluctuations in this context.
To comprehend the effects of thermal fluctuations, the scientists from Innsbruck collaborated with the Danish theoretical group led by Thomas Pohl. Together, they developed a theoretical model, which was published in Nature Communications, to explain the experimental findings. The model highlights the idea that heating the quantum liquid can lead to the formation of a quantum crystal. Remarkably, the model demonstrates that these structures can form more readily as the temperature rises.
Francesca Ferlaino remarks, “With the new model, we now possess a phase diagram for the first time that illustrates the emergence of a supersolid state based on temperature variations.” This intriguing behavior, contradicting our everyday observations, arises from the anisotropic nature of the dipole-dipole interaction between the highly magnetic dysprosium atoms.
Source: University of Innsbruck