TY - JOUR
T1 - High-density two-dimensional electron system induced by oxygen vacancies in ZnO
AU - Rödel, T. C.
AU - Dai, J.
AU - Fortuna, F.
AU - Frantzeskakis, E.
AU - Le Fèvre, P.
AU - Bertran, F.
AU - Kobayashi, M.
AU - Yukawa, R.
AU - Mitsuhashi, T.
AU - Kitamura, M.
AU - Horiba, K.
AU - Kumigashira, H.
AU - Santander-Syro, A. F.
N1 - Funding Information:
We thank S. Sengupta and M. Monteverde for discussions. Work at CSNSM was supported by public grants from the French National Research Agency (ANR), project LACUNES No. ANR-13-BS04-0006-01, and the “Laboratoire d'Excellence Physique Atomes Lumière Matière” (LabEx PALM projects ELECTROX and 2DEG2USE) overseen by the ANR as part of the “Investissements d'Avenir” program (reference: ANR-10-LABX-0039). Work at KEK-PF was supported by Grants-in-Aid for Scientific Research (Grants No. 16H02115 and No. 16KK0107) from the Japan Society for the Promotion of Science (JSPS). Experiments at KEK-PF were performed under the approval of the Program Advisory Committee (Proposals 2016G621 and 2015S2005) at the Institute of Materials Structure Science at KEK. T.C.R. acknowledges funding from the RTRA–Triangle de la Physique (project PEGASOS). A.F.S.-S. thanks support from the Institut Universitaire de France.
PY - 2018/5/14
Y1 - 2018/5/14
N2 - We realize a two-dimensional electron system (2DES) in ZnO by simply depositing pure aluminum on its surface in ultrahigh vacuum and characterize its electronic structure by using angle-resolved photoemission spectroscopy. The aluminum oxidizes into alumina by creating oxygen vacancies that dope the bulk conduction band of ZnO and confine the electrons near its surface. The electron density of the 2DES is up to two orders of magnitude higher than those obtained in ZnO heterostructures. The 2DES shows two s-type subbands, that we compare with the d-like 2DESs in titanates, with clear signatures of many-body interactions that we analyze through a self-consistent extraction of the system self-energy and a modeling as a coupling of a two-dimensional Fermi liquid with a Debye distribution of phonons.
AB - We realize a two-dimensional electron system (2DES) in ZnO by simply depositing pure aluminum on its surface in ultrahigh vacuum and characterize its electronic structure by using angle-resolved photoemission spectroscopy. The aluminum oxidizes into alumina by creating oxygen vacancies that dope the bulk conduction band of ZnO and confine the electrons near its surface. The electron density of the 2DES is up to two orders of magnitude higher than those obtained in ZnO heterostructures. The 2DES shows two s-type subbands, that we compare with the d-like 2DESs in titanates, with clear signatures of many-body interactions that we analyze through a self-consistent extraction of the system self-energy and a modeling as a coupling of a two-dimensional Fermi liquid with a Debye distribution of phonons.
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U2 - 10.1103/PhysRevMaterials.2.051601
DO - 10.1103/PhysRevMaterials.2.051601
M3 - Article
AN - SCOPUS:85059593406
VL - 2
JO - Physical Review Materials
JF - Physical Review Materials
SN - 2475-9953
IS - 5
M1 - 051601
ER -