TY  - JOUR
AU  - Barnett, Julian
AU  - Rose, Marc‐André
AU  - Ulrich, Georg
AU  - Lewin, Martin
AU  - Kästner, Bernd
AU  - Hoehl, Arne
AU  - Dittmann, Regina
AU  - Gunkel, Felix
AU  - Taubner, Thomas
TI  - Phonon‐Enhanced Near‐Field Spectroscopy to Extract the Local Electronic Properties of Buried 2D Electron Systems in Oxide Heterostructures
JO  - Advanced functional materials
VL  - 30
IS  - 46
SN  - 1616-3028
CY  - Weinheim
PB  - Wiley-VCH
M1  - FZJ-2020-03258
SP  - 2004767
PY  - 2020
AB  - In the family of functional oxide materials, the interface between LaAlO3 and SrTiO3 (LAO/STO) is an interesting example, as both materials are large‐bandgap insulators in their bulk state but give rise to a confined 2D electron gas (2DEG) when combined through thin‐film deposition. While this 2DEG exhibits remarkable properties, its experimental investigation is mostly limited to destructive or non‐local (i.e. averaging over larger areas) methods until recently. Scanning near‐field optical microscopy is shown to overcome this limitation, detecting buried 2DEGs by using highly confined optical near‐fields. Here, a full spectroscopic approach with phonon‐enhancement and simulations based on the finite dipole model is combined to extract quantitative electronic properties of the interfacial LAO/STO 2DEG. This threefold improvement compared to previous work will enable the quantitative nanoscale, non‐destructive, sub‐surface analysis of complex oxide thin films and interfaces, as well as similar heterostructures.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000567443000001
DO  - DOI:10.1002/adfm.202004767
UR  - https://juser.fz-juelich.de/record/884796
ER  -