Model frequency shifts from real and imaginary self-energy. Compare bare modes, broadened peaks, and lifetimes. Built for phonon analysis, Raman studies, and solid-state teaching.
| Mode | Bare Frequency (cm⁻¹) | Total Shift (cm⁻¹) | Renormalized Frequency (cm⁻¹) | Intrinsic FWHM (cm⁻¹) | Lifetime (ps) |
|---|---|---|---|---|---|
| Optical Mode A | 520.00 | -2.77 | 517.23 | 4.00 | 1.3272 |
| Optical Mode B | 403.50 | -1.65 | 401.85 | 3.20 | 1.6590 |
| Acoustic Edge | 118.00 | -0.52 | 117.48 | 1.60 | 3.3180 |
| Zone-Center Raman | 300.20 | -1.20 | 299.00 | 2.80 | 1.8960 |
Effective frequency shift: Δeff = ReΣ + Δstrain + Δcarrier
Strain shift: Δstrain = -γG × ε × ω0
Carrier shift: Δcarrier = C × np
Renormalized frequency: ωR = ω0 + Δeff
Intrinsic half width: Γint = |ImΣ| + Γanh + Γdef
Intrinsic full width: FWHMint = 2 × Γint
Observed width: FWHMobs = √(FWHMint² + FWHMinstrument²)
Phonon lifetime: τ(ps) = 5.30884 / FWHMint(cm⁻¹)
Mean free path: ℓ(nm) = vg × τ(ps) × 10⁻³
Bose occupation: nB = 1 / [exp(1.438776877 × ωR / T) - 1]
This calculator combines direct self-energy input with practical strain, carrier, defect, and instrument corrections. It is useful for quick screening and teaching. It is not a full first-principles many-body solver.
Enter the bare phonon frequency from theory, experiment, or literature.
Add the direct real self-energy when you already know the frequency correction from fitting, perturbation theory, or spectral analysis.
Enter the imaginary self-energy as a positive damping magnitude. Then add extra anharmonic and defect broadening if needed.
Use the strain field for tensile or compressive effects. Positive strain with a positive Grüneisen parameter lowers the mode frequency in this simple model.
Use the carrier section when doping or free carriers shift the phonon peak. The coefficient controls direction and magnitude.
Enter instrumental width to estimate the measured linewidth, not the intrinsic lifetime.
Press Calculate. The result appears above the form, under the header. Then export the output as CSV or PDF.
Phonon self-energy describes how interactions modify a vibrational mode. It is central in lattice dynamics, Raman analysis, infrared spectroscopy, and thermal transport studies. The real part shifts the phonon frequency. The imaginary part broadens the peak. Together they control renormalization, damping, and lifetime.
The real term changes the observed frequency from the bare harmonic value. This shift can come from electron-phonon coupling, phonon-phonon scattering, strain, screening, or defects. A softer mode often signals stronger interactions or structural instability. A harder mode may reflect reduced screening or compressive effects.
The imaginary term measures damping. Larger damping means a broader spectral line and a shorter lifetime. That matters in Raman peak fitting, neutron scattering, ultrafast spectroscopy, and thermal conductivity modeling. A narrow linewidth usually means a longer-lived phonon and weaker scattering. A broad line often suggests disorder, anharmonicity, or carrier-induced decay channels.
This calculator gives a practical estimate of renormalized phonon behavior. It combines direct self-energy input with useful corrections for strain, carriers, defects, and instrumental broadening. It also reports lifetime, quality factor, mean free path, energy, and Bose occupation. These outputs help compare conditions quickly.
Use it for fast screening before deeper simulation. It is helpful in semiconductor phonon studies, oxide materials research, nanostructure analysis, and solid-state teaching. It also supports peak interpretation when you need a consistent workflow for frequency shift and linewidth trends. For publication-grade many-body work, use this as an informed estimate and then compare with full Green function or first-principles calculations.
It describes how interactions change a phonon’s ideal behavior. The real part shifts frequency. The imaginary part adds damping and linewidth. Both are essential in spectroscopy and transport analysis.
This calculator uses the damping magnitude |ImΣ| for convenience. That keeps linewidth and lifetime calculations simple. It avoids sign confusion while preserving physical broadening.
No. It is a compact analytical calculator. It is best for screening, fitting support, teaching, and quick comparisons. Full many-body or ab initio workflows need specialized simulation tools.
The calculator uses wavenumbers in cm⁻¹. That matches common Raman and infrared practice. Lifetime, energy, and THz outputs are derived from that same frequency basis.
Real experiments often show shifts from doping and deformation. These effects are not always supplied directly as ReΣ. The added terms make the estimate more practical for applied materials work.
No. Lifetime should be linked to intrinsic linewidth. Instrumental broadening changes the measured peak width, but not the physical decay time of the phonon.
Quality factor is the ratio of renormalized frequency to observed linewidth. Higher values indicate a sharper and more weakly damped resonance. It is useful for comparing mode coherence.
Trust it most for quick estimates, sensitivity checks, and educational use. It performs best when your inputs come from fitted spectra, measured linewidths, or well-calibrated material parameters.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.