High-Mobility Ambipolar Magnetotransport in Topological Insulator Bi2Se3 Nanoribbons
Artikel i vetenskaplig tidskrift, 2021

Nanoribbons of topological insulators (TIs) have been suggested for a variety of applications exploiting the properties of the topologically protected surface Dirac states. In these proposals it is crucial to achieve a high tunability of the Fermi energy, through the Dirac point while preserving a high mobility of the involved carriers. Tunable transport in TI nanoribbons has been achieved by chemical doping of the materials so to reduce the bulk carriers' concentration, however at the expense of the mobility of the surface Dirac electrons, which is substantially reduced. Here we study bare Bi2Se3 nanoribbons transferred on a variety of oxide substrates and demonstrate that the use of a large relative permittivity SrTiO3 substrate enables the Fermi energy to be tuned through the Dirac point and an ambipolar field effect to be obtained. Through magnetotransport and Hall conductance measurements, performed on single Bi2Se3 nanoribbons, we demonstrate that electron and hole carriers are exclusively high-mobility Dirac electrons, without any bulk contribution. The use of SrTiO3 allows therefore an easy field effect gating in TI nanostructures providing an ideal platform to take advantage of the properties of topological surface states.

Författare

Gunta Kunakova

Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantkomponentfysik

Latvijas Universitate

Thilo Bauch

Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantkomponentfysik

Xavier Palermo

Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantkomponentfysik

Matteo Salvato

Universita degli Studi di Roma Tor Vergata

Jana Andzane

Latvijas Universitate

Donats Erts

Latvijas Universitate

Floriana Lombardi

Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantkomponentfysik

Physical Review Applied

2331-7019 (eISSN)

Vol. 16 2 024038

High Frequency Topological Insulator devices for Metrology (HiTIMe)

Europeiska kommissionen (EU) (766714), 2018-02-01 -- 2022-01-31.

Ämneskategorier

Atom- och molekylfysik och optik

Materialkemi

Den kondenserade materiens fysik

DOI

10.1103/PhysRevApplied.16.024038

Mer information

Senast uppdaterat

2021-09-03