Development of a versatile micro-focused angle-resolved photoemission spectroscopy system with Kirkpatrick-Baez mirror optics

TL;DR

This paper presents a new versatile micro-ARPES system using Kirkpatrick-Baez mirror optics, enabling high-precision spatially resolved electronic structure measurements of quantum materials.

Contribution

The development of a micro-ARPES system with monolithically installed Kirkpatrick-Baez mirrors and five-axes motion for precise, high-resolution electronic state mapping.

Findings

Beam spot size of 10x12 μm achieved

Enabled detailed band-structure mapping

Observed a small band anomaly near sample edge

Abstract

Angle-resolved photoemission spectroscopy using a micro-focused beam spot (micro-ARPES) is becoming a powerful tool to elucidate key electronic states of exotic quantum materials. We have developed a versatile micro-ARPES system based on synchrotron radiation beam focused with a Kirkpatrick-Baez mirror optics. The mirrors are monolithically installed on a stage, which is driven with five-axes motion, and are vibrationally separated from the ARPES measurement system. Spatial mapping of the Auphotolithography pattern on Si signifies the beam spot size of 10 $\mu$m (horizontal) x 12 $\mu$m (vertical) at the sample position, which is well suited to resolve the fine structure in local electronic states. Utilization of the micro beam and the high precision sample motion system enables the accurate spatially resolved band-structure mapping, as demonstrated by the observation of a small band anomaly associated with tiny sample bending near the edge of a cleaved topological insulator single crystal.