In-situ angle-resolved photoemission spectroscopy of copper-oxide thin films synthesized by molecular beam epitaxy

TL;DR

This paper introduces a new integrated system combining oxide molecular beam epitaxy with ARPES and SI-STM, enabling detailed electronic structure studies of complex oxides like LSCO thin films.

Contribution

It presents the first experimental ARPES results on LSCO thin films grown by OMBE using a novel multi-module system at BNL.

Findings

Successful ARPES measurement of LSCO thin film electronic structure

Expansion of ARPES applicability to complex oxide thin films

Demonstration of system's capability for future electronic structure studies

Abstract

Angle-resolved photoemission spectroscopy (ARPES) is the key momentum-resolved technique for direct probing of the electronic structure of a material. However, since it is very surface-sensitive, it has been applied to a relatively small set of complex oxides that can be easily cleaved in ultra-high vacuum. Here we describe a new multi-module system at Brookhaven National Laboratory (BNL) in which an oxide molecular beam epitaxy (OMBE) is interconnected with an ARPES and a spectroscopic-imaging scanning tunneling microscopy (SI-STM) module. This new capability largely expands the range of complex-oxide materials and artificial heterostructures accessible to these two most powerful and complementary techniques for studies of electronic structure of materials. We also present the first experimental results obtained using this system - the ARPES studies of electronic band structure of a La$_{2-x}$Sr$_x$CuO$_4$ (LSCO) thin film grown by OMBE.