High resolution electron energy loss spectroscopy with two-dimensional energy and momentum mapping.
High resolution electron energy loss spectroscopy (HREELS) is a powerful technique to probe vibrational and electronic excitations at surfaces. The dispersion relation of surface excitations, i.e., energy as a function of momentum, has in the past, been obtained by measuring the energy loss at a fixed angle (momentum) and then rotating sample, monochromator, or analyzer. Here, we introduce a new strategy for HREELS, utilizing a specially designed lens system with a double-cylindrical Ibach-type monochromator combined with a commercial VG Scienta hemispherical electron energy analyzer, which can simultaneously measure the energy and momentum of the scattered electrons. The new system possesses high angular resolution (<0.1°), detecting efficiency and sampling density. The capabilities of this system are demonstrated using Bi2Sr2CaCu2O(8+δ). The time required to obtain a complete dispersion spectrum is at least one order of magnitude shorter than conventional spectrometers, with improved momentum resolution and no loss in energy resolution.
Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
Xuetao
X
Zhu
Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
Yanwei
Y
Cao
Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
Shuyuan
S
Zhang
Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
Xun
X
Jia
Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
Qinlin
Q
Guo
Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
Fang
F
Yang
Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
Linfan
L
Zhu
Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70808, USA.
Jiandi
J
Zhang
Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70808, USA.
E W
EW
Plummer
Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
Jiandong
J
Guo