Quantitative regulation of electron–phonon coupling

Abstract Electron–phonon (e–p) coupling plays a crucial role in various physical phenomena, and regulation of e–p coupling is vital for the exploration and design of high-performance materials. However, the current research on this topic lacks accurate quantification, hindering further understanding of the underlying physical processes and its applications. In this work, we demonstrate quantitative regulation of e–p coupling, by pressure engineering and in-situ spectroscopy. We successfully observe both a distinct vibrational mode and a strong Stokes shift in layered CrBr 3 , which are clear signatures of e–p coupling. This allows us to achieve precise quantification of the Huang–Rhys factor S at the actual sample temperature, thus accurately determining the e–p coupling strength. We further reveal that pressure efficiently regulates the e–p coupling in CrBr 3 , evidenced by a remarkable 40% increase in S value. Our results offer an approach for quantifying and modulating e–p coupling, which can be leveraged for exploring and designing functional materials with targeted e–p coupling strengths.