Title: PbTe(111) Sub-Thermionic Photocathode: A Route to High-Quality Electron Pulses,
Abstract: The emission properties of PbTe(111) single crystal have been extensively
investigated to demonstrate that PbTe(111) is a promising low root mean square
transverse momentum ({\Delta}p$_T$) and high brightness photocathode. The
density functional theory (DFT) based photoemission analysis successfully
elucidates that the 'hole-like' {\Lambda}$^+_6$ energy band in the $L$ valley
with low effective mass $m^*$ results in low {\Delta}p$_T$. Especially, as a
300K solid planar photocathode, Te-terminated PbTe(111) single crystal is
expected to be a potential 50K electron source.