Abstract
Angle-resolved photoemission spectroscopy with low-energy tunable photons along the nodal direction of oxygen isotope substituted reveals a distinct oxygen isotope shift near the electron-boson coupling “kink” in the electronic dispersion. The magnitude (a few meV) and direction of the kink shift are as expected due to the measured isotopic shift of phonon frequency, and are also in agreement with theoretical expectations. This demonstrates the participation of the phonons as dominant players, as well as pinpointing the most relevant of the phonon branches.
- Received 16 June 2008
DOI:https://doi.org/10.1103/PhysRevLett.101.157005
©2008 American Physical Society