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arXiv · 1910.14068

High resolution time- and angle-resolved photoemission spectroscopy with 11 eV laser pulses

Changmin Lee·Timm Rohwer·Edbert J. Sie·Alfred Zong·Edoardo Baldini·Joshua Straquadine·Philip Walmsley·Dillon Gardner·Young S. Lee·Ian R. Fisher·Nuh Gedik
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Abstract

Performing time and angle resolved photoemission spectroscopy (tr-ARPES) at high momenta necessitates extreme ultraviolet laser pulses, which are typically produced via high harmonic generation (HHG). Despite recent advances, HHG-based setups still require large pulse energies (hundreds of $μ$J to mJ) and their energy resolution is limited to tens of meV. Here, we present a novel 11 eV tr-ARPES setup that generates a flux of $5\times10^{10}$ photons/s and achieves an unprecedented energy resolution of 16 meV. It can be operated at high repetition rates (up to 250 kHz) while using input pulse energies down to 3 $μ$J. We demonstrate these unique capabilities by simultaneously capturing the energy and momentum resolved dynamics in two well-separated momentum space regions of a charge density wave material ErTe$_3$. This novel setup offers opportunity to study the non-equilibrium band structure of solids with exceptional energy and time resolutions at high repetition rates.

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Changmin Lee, Timm Rohwer, Edbert J. Sie, Alfred Zong, Edoardo Baldini, Joshua Straquadine, Philip Walmsley, Dillon Gardner, Young S. Lee, Ian R. Fisher, Nuh Gedik. 2019-10-30. High resolution time- and angle-resolved photoemission spectroscopy with 11 eV laser pulses. https://doi.org/10.1063/1.5139556

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