"Discovery of Hubbard Exciton Sheds Light on Strongly Correlated Insulators"
Scientists led by Dr. David Hsieh have observed evidence of stable Hubbard excitons in a photo-doped antiferromagnetic Mott insulator, Sr2IrO4. Hubbard excitons are composite particles that emerge when an electron and a hole interact through electrostatic forces. Unlike regular excitons in semiconductors, Hubbard excitons in Mott insulators are challenging to detect due to complex electronic interactions and the short-lived nature of these excitons. The team used terahertz radiation and a stroboscopic technique to capture the transient response of Sr2IrO4 and detect the spectra of the Hubbard exciton. This discovery opens up possibilities for fundamental understanding and potential practical applications.