Dufresne S K Y, Zhdanovich S, Michiardi M, Guislain B G, Zonno M, Mazzotti V, O'Brien L, Kung S, Levy G, Mills A K, Boschini F, Jones D J, Damascelli A
Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada.
Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada.
Rev Sci Instrum. 2024 Mar 1;95(3). doi: 10.1063/5.0176170.
We present the development of a versatile apparatus for 6.2 eV laser-based time and angle-resolved photoemission spectroscopy with micrometer spatial resolution (time-resolved μ-ARPES). 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 fluence up to 3 mJ/cm2, this time-resolved μ-ARPES system enables the measurement of ultrafast electron dynamics in exfoliated and inhomogeneous materials. We demonstrate the performance of our system by correlating the spectral broadening of the topological surface state of Bi2Se3 with the spatial dimension of the probe pulse, as well as resolving the spatial inhomogeneity contribution to the observed spectral broadening. Finally, after in situ exfoliation, we performed time-resolved μ-ARPES on a ∼30 μm flake of transition metal dichalcogenide WTe2, thus demonstrating the ability to access ultrafast electron dynamics with momentum resolution on micro-exfoliated materials.
我们展示了一种多功能装置的研发成果，该装置用于基于6.2 eV激光的具有微米级空间分辨率的时间和角度分辨光电子能谱（时间分辨μ-ARPES）。该装置结合了低至约11μm的可调空间分辨率、高能量分辨率（约11 meV）、接近变换极限的时间分辨率（约280 fs）以及高达3 mJ/cm²的可调1.55 eV泵浦通量，这种时间分辨μ-ARPES系统能够测量剥离的和不均匀材料中的超快电子动力学。我们通过将Bi2Se3拓扑表面态的光谱展宽与探测脉冲的空间维度相关联，以及解析对观测到的光谱展宽的空间不均匀性贡献，来展示我们系统的性能。最后，在原位剥离后，我们对约30μm的过渡金属二卤化物WTe2薄片进行了时间分辨μ-ARPES，从而证明了在微剥离材料上以动量分辨率获取超快电子动力学的能力。
