High Resolution Angle Resolved Photoemission with Tabletop 11eV Laser

TL;DR

This paper presents a novel tabletop VUV laser source for high-resolution ARPES, enabling detailed electronic structure studies of quantum materials with resolutions comparable to synchrotrons.

Contribution

The development of a compact, high-flux, tunable VUV laser source for ARPES with sub-meV energy resolution and full Brillouin zone access is a significant advancement.

Findings

Achieved energy resolution better than 2 meV

Demonstrated full Brillouin zone access up to 1.2 Å$^{-1}$

Showcased applications on various quantum materials

Abstract

We developed a table-top vacuum ultraviolet (VUV) laser with $113.778$nm wavelength (10.897eV) and demonstrated its viability as a photon source for high resolution angle-resolved photoemission spectroscopy (ARPES). This sub-nanosecond pulsed VUV laser operates at a repetition rate of 10MHz, provides a flux of 2$\times$10$^{12}$ photons/second, and enables photoemission with energy and momentum resolutions better than 2meV and 0.012\AA$^{-1}$, respectively. Space-charge induced energy shifts and spectral broadenings can be reduced below 2meV. The setup reaches electron momenta up to 1.2\AA$^{-1}$, granting full access to the first Brillouin zone of most materials. Control over the linear polarization, repetition rate, and photon flux of the VUV source facilitates ARPES investigations of a broad range of quantum materials, bridging the application gap between contemporary low energy laser-based ARPES and synchrotron-based ARPES. We describe the principles and operational characteristics of this source, and showcase its performance for rare earth metal tritellurides, high temperature cuprate superconductors and iron-based superconductors.