Debye Material, Drude Material, and Lorentz Material
  • Material
  • Debye
  • Drude
  • Lorentz

Debye Material, Drude Material, and Lorentz Material

This section describes Debye material, Drude material, and Lorentz material.

Debye material, Drude material, and Lorentz material are types of material models that are determined based on dispersion formulas.

Debye Material

Debye materials are commonly used for dispersive material models that are represented as εtotal(f)\varepsilon_{total}(f). For a Debye material with a single pole (p=1p = 1), the relation between the permittivity εtotal\varepsilon_{total} and the frequency ff is expressed as:

εtotal(f)=ε+Δεp1+i2πfγp\varepsilon_{total}(f) = \varepsilon + \frac{\Delta\varepsilon_p}{1 + i2\pi f \gamma_p }

Wherein, ε\varepsilon represents the permittivity;

Δεp\Delta\varepsilon_p represents the change in relative permittivity caused by the Debye pole, also referred to as Debye permittivity (εp\varepsilon_p), which is defined as Δεp=εs,pε,p\Delta\varepsilon_p = \varepsilon_{s,p} - \varepsilon_ {\infty,p}; εs,p\varepsilon_{s,p} represents relative permittivity at stable or zero frequency; ε,p\varepsilon_{\infty,p} represents relative permittivity at infinite frequency;

γp\gamma_p represents pole relaxation time.

Name Symbol Units Range Default Description
Permittivity ε\varepsilon ~ Real number, ε1\varepsilon\geq1 1 Real part of the permittivity εtotal\varepsilon_{total}, dispersion-free
Debye permittivity Δεp\Delta\varepsilon_p ~ Real number, Δεp0\Delta\varepsilon_p \geq0 0 Imaginary part of the complex permittivity εtotal\varepsilon_{total}, Debye permittivity, dispersion-dependent
The pole relaxation time coefficient γp\gamma_p ~ Real number, γp0\gamma_p\geq0 0 Coefficient of pole relaxation time, dispersion-dependent

Material Setting

In the Materials library window, you can add a Debye material model by selecting Add material>Add new material>Add debye material, and modify the material parameters of the Debye model in the pop-up editing interface to create the desired Debye material model.

Drude Material

Drude materials are used to describe metallic dispersive material models that are represented using the permittivity εtotal(f)\varepsilon_{total}(f). For a Drude material with a single pole (p=1p = 1), the relation between the permittivity εtotal\varepsilon_{total} and the frequency ff is expressed as:

εtotal(f)=ε+ωp2(2πf)2+j2πfγp\varepsilon_{total}(f) = \varepsilon + \frac{\omega_p^2}{-(2\pi f)^2 + j2\pi f\gamma_p}

Wherein, ε\varepsilon represents the permittivity;

Name Symbol Units Range Default Description
Permittivity ε\varepsilon ~ Real number, ε1\varepsilon\geq1 1 Real part of the permittivity εtotal\varepsilon_{total}, dispersion-free
Drude pole frequency ωp\omega_p rad/srad/s Real number, ωp0\omega_p \geq0 0 Angular frequency at the Drude pole, dispersion-dependent
Inverse of the pole relaxation time γp\gamma_p rad/srad/s Real number, γp0\gamma_p\geq0 0 Reciprocal of the pole relaxation time coefficient, dispersion-dependent

Material Setting

In the Materials library window, you can add a Drude material model by selecting Add material>Add new material>Add drude material, and modify the material parameters of the Drude model in the pop-up editing interface to create the desired Drude material model.

Lorentz Material

Lorentz materials are typically used for dispersive material models that are represented as εtotal(f)\varepsilon_{total}(f). For a Lorentz material with a single pole (p=1p = 1), the relation between the permittivity εtotal\varepsilon_{total} and the frequency ff is expressed as:

εtotal(f)=ε+εpωp2ωp2+4πjγpf(2πf)2\varepsilon_{total}(f) = \varepsilon + \frac{\varepsilon_p\cdot\omega_p^2}{\omega_p^2 + 4\pi j\gamma_p\cdot f - (2\pi f)^2}

Wherein, ε\varepsilon represents the permittivity;
εp\varepsilon_p represents the Lorentz permittivity;
ωp\omega_p represents the angular frequency at the Lorentz pole;
and γp\gamma_p represents the Lorentz damping coefficient.

Name Symbol Units Range Default Description
Permittivity ε\varepsilon ~ Real number, ε1\varepsilon\geq1 1 Real part of the permittivity εtotal\varepsilon_{total}, dispersion-free
Lorentz permittivity εp\varepsilon_p ~ Real number, εp0\varepsilon_p \geq0 0 Permittivity at the Lorentz pole, dispersion-dependent
Lorentz pole frequency ωp\omega_p rad/srad/s Real number, ωp0\omega_p \geq0 0 Angular frequency at the Lorentz pole, dispersion-dependent
Lorentz damping coefficient γp\gamma_p ~ Real number, γp0\gamma_p\geq0 0 Lorentz damping coefficient (ωp>γp\omega_p>\gamma_p)

Material Setting

In the Materials library window, you can add a Lorentz material model by selecting Add material>Add new material>Add lorentz material, and modify the material parameters of Lorentz model in the pop-up editing interface to create the desired Lorentz material model.