Electron-Beam Source with a Superconducting Niobium Tip
Cameron Johnson, Andreas K. Schmid, Marián Maňkoš, Robin Röpke, Nicole Kerker, Ing‐Shouh Hwang, Ed Wong, D. Frank Ogletree, Andrew M. Minor, Alexander Stibor
Abstract
Electron-beam sources are foundational in high-resolution electron microscopy and spectroscopy, but applications have been limited due to their relatively large energy spread. The authors fabricate a monocrystalline niobium nanotip electron field emitter and characterize it in superconducting and normal-conducting regimes. This bright, stable, coherent electron beam source features an exceptionally narrow energy spread. The authors also study the role of xenon adsorption and two-electron correlations. This work may improve aberration-corrected microscopy and electron energy-loss spectroscopy and enable high-resolution vibrational spectroscopy or quantum electron microscopy.