Researchers from the Chinese Academy of Sciences, led by Chu-Tian Gao, have published a study in the journal Physical Review Letters that explores the vestigial phases of a specific type of superconducting state known as the pair-density-wave (PDW). This research could have implications for understanding and developing advanced materials for energy transmission and storage.
The team focused on a two-dimensional (2D) commensurate PDW, which is a state where the pairing of electrons varies periodically in space. This is different from conventional superconductors where the pairing is uniform. The researchers used a combination of theoretical approaches, including Ginzburg-Landau theory, renormalization group (RG) studies, and Monte-Carlo (MC) simulations, to investigate the phases that emerge as the temperature changes.
For PDWs with a small number of wave vectors (n ≤ 4), the study found that as the temperature increases, the system transitions from a superconducting state to a charge-density-wave (CDW) phase. In the CDW phase, the translational symmetry of the system is broken, meaning the charge density varies periodically in space.
For PDWs with a larger number of wave vectors (n ≥ 5), the researchers discovered a more complex behavior. As the temperature increases, the system undergoes two distinct phase transitions. First, it enters a critical-PDW phase, where the discrete translational symmetry is only quasi-broken, leading to a power-law decay of the density-density correlation. Then, it transitions to a critical-CDW phase before eventually restoring full translational symmetry at higher temperatures.
These findings could have practical applications in the energy sector, particularly in the development of superconducting materials for energy transmission and storage. By understanding the behavior of PDWs and their vestigial phases, researchers may be able to design materials with improved properties, such as higher critical temperatures or enhanced stability. However, the direct application of these findings is still a topic for future research.
The study, titled “Critical Density-Wave Vestigial Phases of Commensurate Pair Density Wave,” was published in the journal Physical Review Letters.
This article is based on research available at arXiv.