2021/12/06 by Dominik Christiansen, Christiansen, Dominik, Malte Selig +4
Engineering · Materials Science · #2D Materials and Applications #FOS: Physical sciences #Organic and Molecular Conductors Research #Perovskite Materials and Applications #Strongly Correlated Electrons (cond-mat.str-el)
paper · pdf · doi:10.48550/arxiv.2112.03135
openalex publication_date 2021/12/06 · openalex created_date 2021/12/31 · openalex updated_date 2026/07/28
The excitonic insulator is an elusive electronic phase exhibiting a correlated excitonic ground state. Materials with such a phase are expected to have intriguing properties such as excitonic high-temperature superconductivity. However, compelling evidence on the experimental realization is still missing. Here, we theoretically propose hybrids of two-dimensional semiconductors functionalized by organic molecules as prototypes of excitonic insulators, with the exemplary candidate WS2-F6TCNNQ. This material system exhibits an excitonic insulating phase at room temperature with a ground state formed by a condensate of interlayer excitons. To address an experimentally relevant situation, we calculate the corresponding phase diagram for the important parameters: temperature, gap energy, and dielectric environment. Further, to guide future experimental detection, we show how to optically characterize the different electronic phases via far-infrared to terahertz (THz) spectroscopy.