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Designing atomic-scale resistive circuits in topological insulators through vacancy-induced localized modes
Cunyuan Jiang1,2, Weicen Dong1,2, Matteo Baggioli1,2
1School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China.
Journal of Physics. Condensed Matter : an Institute of Physics Journal
|November 25, 2025
Summary
Structural defects like vacancies in topological insulators can create unique electronic modes. These modes may enable the design of atomic-scale resistive circuits, offering new possibilities in materials science.
Area of Science:
- Condensed matter physics
- Materials science
- Quantum mechanics
Background:
- Topological insulators possess unique electronic properties protected by topology.
- Structural defects, such as vacancies, can significantly influence material properties.
- Localized electronic excitations and chiral modes are key phenomena in topological materials.
Purpose of the Study:
- To investigate the induction of localized electronic excitations by vacancies in topological insulators.
- To explore the emergence of one-dimensional chiral bulk modes from closely spaced vacancies.
- To propose and analyze the potential of vacancies for designing atomic-scale resistive circuits.
Main Methods:
- Utilizing a tight-binding Hamiltonian model to describe the dynamics of chiral bulk modes.
- Calculating the hopping parameter based on the overlap of electronic wave functions between adjacent vacancies.
- Estimating circuit resistance as a function of vacancy distribution and geometric properties.
Main Results:
- Vacancies can induce topologically protected localized electronic excitations.
- Sufficiently close vacancies give rise to one-dimensional propagating chiral bulk modes.
- The tight-binding model accurately predicts the low-energy spectrum of these modes.
- The resistance of vacancy-based circuits is dependent on the geometric arrangement of vacancies.
Conclusions:
- Vacancies in topological materials offer a pathway to engineer novel electronic functionalities.
- The phenomenon provides a basis for designing atomic-scale resistive circuits.
- Further research can explore the precise control of resistance through vacancy engineering.
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