Fig. 1. (a) Schematic diagram of the proposed metal–insulator–metal waveguide. The yellow parts are Dirac semimetal layers. The green part is SU-8 layer. The blue part is SiO₂. (b) The top layer of the proposed unit cell. (c) The middle layer of the proposed unit cell. (d) The bottom layer of the proposed unit cell. The thickness of SU-8 layer and SiO₂ layer is set as 180nm

Fig. 2. (a) The schematic diagram of the proposed structure. (b) Simulated and calculated transmission spectrum of the proposed structure. (c) Schematic diagram of the waveguide without metal reflector layer. (d) Simulated and calculated transmission spectrum of the waveguide without metal reflector layer

Fig. 3. (a) The magnetic field intensity distribution at resonance wavelength 842nm. (b) The magnetic field intensity distribution at resonance wavelength 921nm. (c) The magnetic field intensity distribution at resonance wavelength 900nm. (d) The magnetic field intensity distribution at resonance wavelength 950nm

Fig. 4. (a) The magnetic field intensity distribution at resonance wavelength 1010nm. (b) The magnetic field intensity distribution at resonance wavelength 1061nm. (c) The magnetic field intensity distribution at resonance wavelength 1040nm. (d) The magnetic field intensity distribution at resonance wavelength 1080nm

Fig. 5. The phase spectrum of the proposed structure

Fig. 6. (a) The magnetic field intensity distribution of the waveguide without metal reflector layer at resonance wavelength 840nm. (b) The magnetic field intensity distribution of the waveguide without metal reflector layer at resonance wavelength 940nm. (c) The magnetic field intensity distribution of the waveguide without metal reflector layer at resonance wavelength 885nm. (d) The magnetic field intensity distribution of the waveguide without metal reflector layer at resonance wavelength 973nm

Fig. 7. Transmission spectrum with different Fermi energy

Fig. 8. (a) Imaginary parts of the permittivity of Dirac semimetals layers. (b) Real parts of the permittivity of Dirac semimetals layers

Table 1. 几何参数