Fig. 1. Schematic of the considered quantum dot-SSH chain hybrid system. The hollow circles denote atoms on the leads, the shadow circles are the quantum dots, red circles are the A atoms, the blue circles represent the B atoms. is the hopping amplitude between the two nearest-neighbor atoms on the leads. describes the strength of tunneling coupling between the lead-η and quantum dot-η, is the strength of tunneling coupling between quantum dot and SSH chain, and denote the intra-cell and inter-cell hopping amplitudes, respectively. N is the number of unit cells.

Fig. 2. (a) Energy spectrum of the SSH chain; (b) and (c) Energy spectrum of the quantum dot-SSH chain hybrid system, where (b) and (c) . Here, and .

Fig. 3. (a) The probability distributions of wave functions of the zero-energy modes at each sites in the SSH chain with ; (b)−(d) The probability distributions of wave functions of the zero-energy modes at each sites in the quantum dot-SSH chain hybrid system, where (b) , , (c) , , (d) .

Fig. 4. (a), (c) and (e)Energy spectrum of the quantum dot-SSH chain hybrid system in the vicinity of the zero energy; (b), (d) and (f) Energy spectrum of the quantum dot-SSH chain hybrid system coupled to the first atom (–1) of the left lead and the first atom (1) of the right one in the vicinity of the zero energy at .

Fig. 5. The transmission probability versus the energy of incident electron for different strengths of tunneling coupling at , , and .

Fig. 6. The probability distributions of wave functions of the zero-energy modes at each sites in the quantum dot-SSH chain hybrid system coupled to the first atom (–1) of the left lead and the first atom (1) of the right one. The other parameters are the same as in Fig. 5.

Fig. 7. The transmission probability versus the energy of incident electron for different strengths of tunneling coupling at , and . (a1) and (a2) ; (b1) and (b2) .

Fig. 8. The transmission probability versus the energy of incident electron for different strengths of tunneling coupling at , and . (a1) and (a2) ; (b1) and (b2) .