Quantitative regulation of electron-phonon coupling.

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 andin-situspectroscopy. We successfully observe both a distinct vibrational mode and a strong Stokes shift in layered CrBr₃, which are clear signatures of e-p coupling. This allows us to achieve precise quantification of the Huang-Rhys factorSat the actual sample temperature, thus accurately determining the e-p coupling strength. We further reveal that pressure efficiently regulates the e-p coupling in CrBr₃, evidenced by a remarkable 40% increase inSvalue. 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.