Dielectric disorder in two-dimensional materials
Journal article, 2019

Understanding and controlling disorder is key to nanotechnology and materials science. Traditionally, disorder is attributed to
local fluctuations of inherent material properties such as chemical and structural composition, doping or strain. Here, we present
a fundamentally new source of disorder in nanoscale systems that is based entirely on the local changes of the Coulomb
interaction due to fluctuations of the external dielectric environment. Using two-dimensional semiconductors as prototypes,
we experimentally monitor dielectric disorder by probing the statistics and correlations of the exciton resonances, and theoretically
analyse the influence of external screening and phonon scattering. Even moderate fluctuations of the dielectric environment
are shown to induce large variations of the bandgap and exciton binding energies up to the 100 meV range, often making
it a dominant source of inhomogeneities. As a consequence, dielectric disorder has strong implications for both the optical and
transport properties of nanoscale materials and their heterostructures.

Author

Archana Raja

University of California at Berkeley

Lutz Waldecker

Stanford University

Jonas Zipfel

University of Regensburg

Yeongsu Cho

University of Chicago

Samuel Brem

Chalmers, Physics, Condensed Matter Theory

Jonas Ziegler

University of Regensburg

Marvin Kulig

University of Regensburg

Takashi Taniguchi

National Institute for Materials Science (NIMS)

Kenji Watanabe

National Institute for Materials Science (NIMS)

Ermin Malic

2D-Tech

Chalmers, Physics, Condensed Matter Theory

Tony Heinz

Stanford University

Timothy Berkelbach

Columbia University

Alexey Chernikov

University of Regensburg

Nature Nanotechnology

1748-3387 (ISSN)

Vol. 14 832-837

Subject Categories

Condensed Matter Physics

DOI

10.1038/s41565-019-0520-0

More information

Latest update

9/7/2020 7