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Indirect exchange interaction between magnetic impurities in one-dimensional gapped helical states.

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Electron-electron interactions in partially mixed helical states.

Zeinab Bakhshipour1, Mir Vahid Hosseini1

  • 1Department of Physics, Faculty of Science, University of Zanjan, Zanjan 45371-38791, Iran.

Journal of Physics. Condensed Matter : an Institute of Physics Journal
|June 21, 2024
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Summary

Electron-electron interactions in one-dimensional helical states significantly alter their properties. Strong interactions lead to a dominant spin density wave and unique charge transport behaviors in topological insulators.

Keywords:
electron–electron interactionshelical statesone-dimensional systems

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Area of Science:

  • Condensed Matter Physics
  • Topological Materials
  • Quantum Phenomena

Background:

  • Partially broken time-reversal symmetry in 2D topological insulators creates helical gapped states at their edges.
  • Electron-electron interactions are crucial for understanding the behavior of these one-dimensional edge states.

Purpose of the Study:

  • To theoretically investigate the impact of electron-electron interactions on one-dimensional partially mixed helical states.
  • To map out the phase diagram and identify different interaction regimes.
  • To analyze the resulting charge and spin density wave correlations and their effect on charge transport.

Main Methods:

  • Bosonization method
  • Renormalization group analysis
  • Memory function technique

Main Results:

  • Identification of weak gap, crossover, and strong gap regimes.
  • Strong interactions mix state helicity, creating a relevant strong gap regime.
  • Spin density wave correlations dominate over charge density wave correlations under strong repulsive interactions.
  • Non-uniform temperature dependence of charge conductivity in both weak and strong gap regimes.

Conclusions:

  • Electron-electron interactions play a critical role in determining the properties of helical gapped states.
  • The interplay between interactions and helicity leads to distinct electronic phases and transport characteristics.
  • Understanding these phenomena is key for potential applications in topological electronics.