Extreme ultraviolet time- and angle-resolved photoemission setup with 21.5 meV resolution using high-order harmonic generation from a turn-key Yb:KGW amplifier
Abstract
Characterizing and controlling electronic properties of quantum materials require direct measurements of nonequilibrium electronic band structures over large regions of momentum space. Here, we demonstrate an experimental apparatus for time- and angle-resolved photoemission spectroscopy using high-order harmonic probe pulses generated by a robust, moderately high power (20 W) Yb:KGW amplifier with a tunable repetition rate between 50 and 150 kHz. By driving high-order harmonic generation (HHG) with the second harmonic of the fundamental 1025 nm laser pulses, we show that single-harmonic probe pulses at 21.8 eV photon energy can be effectively isolated without the use of a monochromator. The on-target photon flux can reach 5 × 1010 photons/s at 50 kHz, and the time resolution is measured to be 320 fs. The relatively long pulse duration of the Yb-driven HHG source allows us to reach an excellent energy resolution of 21.5 meV, which is achieved by suppressing the space-charge broadening using a low photon flux of 1.5 × 108 photons/s at a higher repetition rate of 150 kHz. The capabilities of the setup are demonstrated through measurements in the topological semimetal ZrSiS and the topological insulator Sb2−xGdxTe3.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jan 01, 2020
- Source ID
- 10.1063/1.5121425
Entities
People
- Arjun K Pathak
- Christopher Sims
- Dariusz Kaczorowski
- Firoza Kabir
- Gyanendra Dhakal
- John E Beetar
- Klauss Dimitri
- M. Mofazzel Hosen
- Madhab Neupane
- Marc B. Etienne
- Michael Chini
- Sabin Regmi
- Yangyang Liu
- Yong Liu
Organizations
- Ames National Laboratory
- Buffalo State University
- Polish Academy of Sciences
- United States Air Force
- United States Department of Energy
- University of Central Florida