Infrared spectroscopy of two-dimensional electron systems
Journal article, 2019

© 2019, EDP Sciences, Springer-Verlag GmbH Germany, part of Springer Nature. We have used grazing-angle infrared spectroscopy with polarized radiation to detect the Berreman effect (BE) in the two-dimensional electron systems (2DES) which form spontaneously at two interfaces: one between an amorphous film LaAlO3 and its SrTiO3 substrate (LAO/STO), and another at the interface between the topological insulator (TI) Bi2Se3 and its sapphire substrate. In both systems we have thus extracted the 2DES parameters at different temperatures. In the quasi-2DES under amorphous LAO, the surface density ns is higher than under crystalline LAO, while the mobility is nearly the same and the thickness d is 7 nm. In ultrapure Bi2Se3 on sapphire, preliminary data provided d < 1 nm and ns ≈ 1013 cm−2, indicating, by comparison with existing estimates, that the BE indeed detects the topological surface states.


P. Calvani

Sapienza University of Rome

Alexei Kalaboukhov

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

Pavel P. Shibayev

Rutgers, The State University of New Jersey

M. Salehi

Rutgers, The State University of New Jersey

J. Moon

Rutgers, The State University of New Jersey

Seongshik Oh

Rutgers, The State University of New Jersey

E. Falsetti

Sapienza University of Rome

M. Ortolani

Sapienza University of Rome

F. Miletto Granozio

Universita degli Studi di Napoli Federico II

J. B. Brubach

SOLEIL Synchrotron

P. Roy

SOLEIL Synchrotron

A. Nucara

Sapienza University of Rome

European Physical Journal: Special Topics

1951-6355 (ISSN) 1951-6401 (eISSN)

Vol. 228 3 669-673

Subject Categories

Atom and Molecular Physics and Optics

Other Physics Topics

Condensed Matter Physics



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7/8/2019 2