Energy scales revealed by ARPES study on four layered cuprate superconductor Ba$_{2}$Ca$_{3}$Cu$_{4}$O$_{8}$(O$_{\delta }$F$_{1-\delta })_{2}$

Recently discovered four layered cuprate superconductor Ba$_{2}$Ca$_{3}$Cu$_{4}$O$_{8}$(O$_{\delta }$F$_{1-\delta })_{2}$ posseses various properties that differ from the conventional cuprate High T$_{c}$ superconductors, making itself exceptional to the well known high T$_{c}$ superconductivity phase diagram. The understanding of this discrepancy will provide important implications for high T$_{c}$ theory. We study this material by Angular Resolved Photoemission Spectroscopy (ARPES) and find that the electronic band structure of this four layered system exhibits clear difference from the previously studied hole- or electron- doped cuprate superconductors such as Bi2212 or NCCO. The multiple energy scales associated with its electronic structures not only show the complexity of this system, but also provide hints to understand its uniqueness.