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arXiv · 2406.11165

Tunable Fano and Dicke effects in quantum transport of double quantum dots sandwiched between topological insulators

Yuan Hong·Zhen-Guo Fu·Zhou-Wei-Yu Chen·Feng Chi·Zhigang Wang·Wei Zhang·Ping Zhang
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Abstract

We study the quantum transport in double quantum dots (DQD) sandwiched between surfaces of topological insulator (TI) Bi$_{2}$Te$_{3}$, which possess strong spin-orbit coupling (SOC) and $^{d}$C$_{3v}$ double group symmetry. Different from the spin-conserved case with two-dimensional electron gas (2DEG) electrodes, the conductance displays a universal scaling relation for different Fermi energy associated with the topological nature/linear dispersion of topological surface states. The interplay between direct inter-dot tunneling and surface state mediated interaction leads to tunable Dicke and Fano effects with changing the inter-dot distance. We propose nano-rulers with different measurement range and resolution based on the Fano $q$-factor. Furthermore, when applying an in-plane Zeeman field, a crossover from a double-peak shape to a quad-peak shape in conductance curve appears. Moreover, the rotational symmetry of the system could also be revealed from the conductance pattern. Our findings contribute to a better understanding of the quantum transport in the presence of electrode's SOC topological states.

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Yuan Hong, Zhen-Guo Fu, Zhou-Wei-Yu Chen, Feng Chi, Zhigang Wang, Wei Zhang, Ping Zhang. 2024-06-17. Tunable Fano and Dicke effects in quantum transport of double quantum dots sandwiched between topological insulators. https://doi.org/10.1103/physrevb.111.155423

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