Figure 5 Effective index and figure of merit. 3D FDTD simulation Selleck Sorafenib of (a) real part of n eff, (b) imaginary part of n eff, and (c) figure of merit for the different phases of the Bi2Se3 dielectric layer, where the light source is p polarization at normal incidence angle. The refractive index is expressed in terms of the real and imaginary parts of the

permeability μ eff and permittivity ϵ eff. However, the sign of the real part of the permeability μ eff: Real(μ eff) determines the relative magnitudes of the imaginary and real parts of the refractive index [41]. To achieve a negative index with a small loss, a negative Real(μ eff) is required. Therefore, we have simulated μ eff and ϵ eff for the structure as shown in Figure  6. For the trigonal and orthorhombic phases of Bi2Se3, Real(μ eff) has a Fano-type line shape and Im(μ eff) has a Lorentzian line shape in the region of the negative index. Moreover, a double-negative MM can be PLX-4720 in vitro achieved when Real(μ eff) and Real(ϵ eff) simultaneously reach negative values over a wide frequency range

and thus a reduced loss. The maximum negative Real(μ eff) decreases with the phase transition from the trigonal to orthorhombic, hence resulting in the smaller value of the maximum negative Real(n eff) at the orthorhombic phase. Figure 6 Permittivity and permeability. 3D FDTD simulation of (a) the real part of RVX-208 μ eff, (b) the imaginary part of μ eff, (c) the real part of ϵ eff, and (d) the imaginary part of ϵ eff for the different phases of the Bi2Se3 dielectric

layer, where the light source is p polarization at normal incidence angle. This magnetic negative response can be explained looking at the current and field distribution at the resonance wavelengths. Figure  7 shows the current and total magnetic field intensity for the magnetic resonant wavelengths of 2,140 and 1,770 nm at the β plane shown in Figure  1. In the field maps of Figure  7, the arrows show the currents, whereas the color shows the intensity of the magnetic field. It clearly shows that the antiparallel currents are excited at opposite internal metallic interfaces, closed by an electric displacement current J D. Therefore, these virtual current loops between two Au layers on the β plane give rise to magnetic resonant responses of negative Re(μ eff) that interact strongly with the incident magnetic field at which the total magnetic field intensity H is strongly localized in the Bi2Se3 dielectric layer between the top and bottom Au layers [42]. Figure 7 Magnetic field intensity and displacement current.