Large magnetic gap at the Dirac point in Bi2Te3/MnBi2Te4 heterostructures

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216305%3A26620%2F19%3APU135039" target="_blank" >RIV/00216305:26620/19:PU135039 - isvavai.cz</a>

Alternative codes found

RIV/00216224:14310/19:00113420 RIV/49777513:23640/19:43958577

Result on the web

<a href="https://www.nature.com/articles/s41586-019-1826-7" target="_blank" >https://www.nature.com/articles/s41586-019-1826-7</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1038/s41586-019-1826-7" target="_blank" >10.1038/s41586-019-1826-7</a>

Result language

angličtina

Original language name

Large magnetic gap at the Dirac point in Bi2Te3/MnBi2Te4 heterostructures

Original language description

Magnetically doped topological insulators enable the quantum anomalous Hall effect (QAHE), which provides quantized edge states for lossless charge-transport applications(1-8). The edge states are hosted by a magnetic energy gap at the Dirac point(2), but hitherto all attempts to observe this gap directly have been unsuccessful. Observing the gap is considered to be essential to overcoming the limitations of the QAHE, which so far occurs only at temperatures that are one to two orders of magnitude below the ferromagnetic Curie temperature, T-C (ref. (8)). Here we use low-temperature photoelectron spectroscopy to unambiguously reveal the magnetic gap of Mn-doped Bi2Te3, which displays ferromagnetic out-of-plane spin texture and opens up only below T-C. Surprisingly, our analysis reveals large gap sizes at 1 kelvin of up to 90 millielectronvolts, which is five times larger than theoretically predicted(9). Using multiscale analysis we show that this enhancement is due to a remarkable structure modification induced by Mn doping: instead of a disordered impurity system, a self-organized alternating sequence of MnBi2Te4 septuple and Bi2Te3 quintuple layers is formed. This enhances the wavefunction overlap and size of the magnetic gap(10). Mn-doped Bi2Se3 (ref. (11)) and Mn-doped Sb2Te3 form similar heterostructures, but for Bi2Se3 only a nonmagnetic gap is formed and the magnetization is in the surface plane. This is explained by the smaller spin-orbit interaction by comparison with Mn-doped Bi2Te3. Our findings provide insights that will be crucial in pushing lossless transport in topological insulators towards room-temperature applications.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10700 - Other natural sciences

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2019

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

NATURE

ISSN

0028-0836

e-ISSN

1476-4687

Volume of the periodical

576

Issue of the periodical within the volume

7787

Country of publishing house

GB - UNITED KINGDOM

Number of pages

19

Pages from-to

423-441

UT code for WoS article

000504660500092

EID of the result in the Scopus database

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