Time-resolved ARPES on exfoliated 2D materials with micrometer spatial resolution.
ORAL · Invited
Abstract
With its direct correspondence to the electronic structure, angle-resolved photoemission spectroscopy (ARPES) is a ubiquitous tool for the study of quantum materials. When extended to the temporal domain, time-resolved ARPES offers the potential to move beyond equilibrium properties, exploring both the unoccupied electronic structure as well as its dynamical response under ultrafast perturbation [1]. Here we present a versatile apparatus for 6.2 eV laser-based time and angle-resolved photoemission spectroscopy with micrometer spatial resolution [2]. With a combination of tunable spatial resolution down to ∼11 μm, high energy resolution (∼11 meV), near-transform-limited temporal resolution (∼280 fs), and tunable 1.55 eV pump, this time-resolved μ-ARPES system enables the measurement of ultrafast electron dynamics in exfoliated and inhomogeneous materials. We demonstrate its performance by correlating the spectral broadening of the topological surface state of Bi2Se3 with the spatial dimension of the probe pulse. Finally, by performing time-resolved μ-ARPES on in situ exfoliated Ta2NiSe5 as a function of thickness - from bulk down to the monolayer limit - we are able to probe the many-body coherence [3] and eventually the quenching of the excitonic-insulator's condensate.
[1] F. Boschini, M. Zonno, A. Damascelli, Rev. Mod. Phys. 96, 015003 (2024).
[2] S. K. Y. Dufresne et al., Rev. Sci. Instrum. 95, 033907 (2024).
[3] D. Golez et al., Phys. Rev. B 106, L121106 (2022).
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Publication: S. K. Y. Dufresne, S. Zhdanovich, M. Michiardi, B. G. Guislain, M. Zonno, S. Kung, G. Levy, A. K. Mills, F. Boschini, D. J. Jones, A. Damascelli <br>A versatile laser-based apparatus for time-resolved ARPES with micro-scale spatial resolution.<br>Rev. Sci. Instrum. 95, 033907 (2024).<br><br>D. Golez, S. K. Y. Dufresne, M.J. Kim, F. Boschini, H. Chu,Y. Murakami, G. Levy, A. K. Mills, S. Zhdanovich, M. Isobe, H. Takagi, S. Kaiser, P. Werner, D. J. Jones, A. Georges, A. Damascelli, A. J. Millis<br>Unveiling the underlying interactions in Ta2NiSe5 from photoinduced lifetime change.<br>Phys. Rev. B 106, L121106 (2022).
