Oxygen isotope effect on the electronic structure of high-T_c cuprates studied by angle-resolved photoemission spectroscopy

利用低能可调谐光子沿着波节方向的角分辨光电子能谱研究了氧同位素取代的Bi_2Sr_2CaCu_2O_（8+δ）在电子色散中的电子-玻色子耦合“扭折”附近的氧同位素位移。扭结位移的大小（几个meV）和方向是预期的，由于测量的声子频率的同位素位移，也与理论预期一致。这表明声子作为主导参与者的参与，以及精确定位最相关的声子分支。

Angle-resolved photoemission spectroscopy with low-energy tunable photons along the nodal direction of oxygen isotope substituted Bi_2Sr_2CaCu_2O_<8+δ> 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.