TY - JOUR
T1 - Insulator-to-Metal Transition at Oxide Interfaces Induced by WO3 Overlayers
AU - Mattoni, Giordano
AU - Baek, David J.
AU - Manca, Nicola
AU - Verhagen, Nils
AU - Groenendijk, Dirk J.
AU - Kourkoutis, Lena F.
AU - Filippetti, Alessio
AU - Caviglia, Andrea D.
PY - 2017/12/6
Y1 - 2017/12/6
N2 - Interfaces between complex oxides constitute a unique playground for two-dimensional electron systems (2DESs), where superconductivity and magnetism can arise from combinations of bulk insulators. The 2DES at the LaAlO3/SrTiO3 interface is one of the most studied in this regard, and its origin is determined by the polar field in LaAlO3 as well as by the presence of point defects, like oxygen vacancies and intermixed cations. These defects usually reside in the conduction channel and are responsible for a decrease of the electronic mobility. In this work, we use an amorphous WO3 overlayer to obtain a high-mobility 2DES in WO3/LaAlO3/SrTiO3 heterostructures. The studied system shows a sharp insulator-to-metal transition as a function of both LaAlO3 and WO3 layer thickness. Low-temperature magnetotransport reveals a strong magnetoresistance reaching 900% at 10 T and 1.5 K, the presence of multiple conduction channels with carrier mobility up to 80 000 cm2 V-1 s-1, and quantum oscillations of conductance.
AB - Interfaces between complex oxides constitute a unique playground for two-dimensional electron systems (2DESs), where superconductivity and magnetism can arise from combinations of bulk insulators. The 2DES at the LaAlO3/SrTiO3 interface is one of the most studied in this regard, and its origin is determined by the polar field in LaAlO3 as well as by the presence of point defects, like oxygen vacancies and intermixed cations. These defects usually reside in the conduction channel and are responsible for a decrease of the electronic mobility. In this work, we use an amorphous WO3 overlayer to obtain a high-mobility 2DES in WO3/LaAlO3/SrTiO3 heterostructures. The studied system shows a sharp insulator-to-metal transition as a function of both LaAlO3 and WO3 layer thickness. Low-temperature magnetotransport reveals a strong magnetoresistance reaching 900% at 10 T and 1.5 K, the presence of multiple conduction channels with carrier mobility up to 80 000 cm2 V-1 s-1, and quantum oscillations of conductance.
KW - high mobility
KW - LaAlO/SrTiO interface
KW - metal-insulator
KW - quantum oscillations
KW - strong classical magnetoresistance
KW - two-dimensional electron systems
KW - WO overlayers
UR - http://resolver.tudelft.nl/uuid:5757f8cb-e964-4b40-839e-b812d2b5f246
UR - http://www.scopus.com/inward/record.url?scp=85037731502&partnerID=8YFLogxK
U2 - 10.1021/acsami.7b13202
DO - 10.1021/acsami.7b13202
M3 - Article
AN - SCOPUS:85037731502
SN - 1944-8244
VL - 9
SP - 42336
EP - 42343
JO - ACS Applied Materials and Interfaces
JF - ACS Applied Materials and Interfaces
IS - 48
ER -