Dirac Gap Opening and Modifying Mechanism in an Axion Antiferromagnetic Topological Insulator MnBi2Te4

Результат исследований: Научные публикации в периодических изданияхстатьярецензирование

Аннотация

Abstract: The angle-resolved photoelectron spectroscopy with photoexcitation by laser radiation (hν = 6.3 eV) is used to study the modification of the gap open at the Dirac point in an axion antiferromagnetic topological insulator MnBi2Te4 at temperatures higher and lower the Néel temperature (24.5 K). The open gap is shown can have both anomalously high (62–67 meV) and significantly decreased (15–18 meV) values in various MnBi2Te4 samples or various areas of the same sample. In both the cases, the gap remains open above the Néel temperature. As a result of the studies, it is assumed that the difference in the widths of the gaps open at the Dirac point is related to the manifestation of the effect of fractionation of axion term θ. The gap width (62–67 meV) that correlates with the result of theoretical calculations corresponds to the state with axion term θ = π. In this case, the experimental observation of the gap at the Dirac point of 15–18 meV corresponds to the effective modulation of the axion term θ = π/4 due to the generation of many-body chiral spin fluctuations and their interaction upon laser photoexcitation.

Язык оригиналаанглийский
Страницы (с-по)1460-1468
Число страниц9
ЖурналPhysics of the Solid State
Том62
Номер выпуска8
DOI
СостояниеОпубликовано - 1 авг 2020

Предметные области Scopus

  • Электроника, оптика и магнитные материалы
  • Физика конденсатов

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