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Mesoscopic Conductance Fluctuations in 2D HgTe Semimetal
Daniiar Khudaiberdiev1,2, Ze Don Kvon2,3, Matvey V Entin2
1Institute of Solid State Physics, Vienna University of Technology, 1040 Vienna, Austria.
Nanomaterials (Basel, Switzerland)
|November 10, 2023
Summary
Mesoscopic conductance fluctuations were observed in disordered HgTe semimetals. These fluctuations arise from a unique collective state involving percolation networks of electron resistances.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Mesoscopic Physics
Background:
- Strongly disordered two-dimensional (2D) materials exhibit complex electronic behaviors.
- Understanding mesoscopic phenomena is crucial for developing novel electronic devices.
Purpose of the Study:
- To investigate the origin of mesoscopic conductance fluctuations in a HgTe-based semimetal.
- To characterize the dependence of these fluctuations on external parameters and system disorder.
Main Methods:
- Experimental observation of conductance fluctuations in macroscopic HgTe samples.
- Analysis of the fluctuations' dependence on gate voltage, magnetic field, and temperature.
- Correlation of fluctuations with the system's disorder level.
Main Results:
- Mesoscopic conductance fluctuations were identified in the weak localization regime of a disordered 2D HgTe semimetal.
- These fluctuations exhibit anomalous dependencies on gate voltage, magnetic field, and temperature.
- Fluctuations were absent in the electron metal regime and strongly correlated with disorder.
Conclusions:
- The observed fluctuations originate from a collective state involving a percolation network of electron resistances.
- This network is likely formed by a fluctuation potential exceeding the Fermi level at low electron densities.
- The findings provide insights into charge transport mechanisms in strongly disordered 2D systems.
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