LESCO Charge excitation pure intensity

This report analyzes the pure intensity (without temperature subtraction) from the processed LESCO RIXS dataset. The same preprocessed spectra are used as in the intensity-difference analysis: elastic background removed, dd-normalized intensity, and aligned elastic position.

The low-energy range contains mixed contributions from charge excitations and phonons. In this report we retain the full temperature-resolved intensity and examine:

1. 2D intensity maps at all measured temperatures,
2. 1D energy-loss cuts across momentum,
3. energy-integrated trends (energy loss > 10 meV) versus momentum and temperature.

This provides a complementary view to the difference-based report by preserving the absolute temperature-dependent signal level.

We model the measured signal as

$$I(T, q, \omega) = I_{\mathrm{charge}}(T, q, \omega) + I_{\mathrm{phonon}}(T, q, \omega).$$

For the energy-integrated analysis used here,

$$I_{\mathrm{int}}(T, q) = \int_{\omega > 10\ \mathrm{meV}} I(T, q, \omega)\, d\omega = \int_{\omega > 10\ \mathrm{meV}} I_{\mathrm{charge}}\, d\omega + \int_{\omega > 10\ \mathrm{meV}} I_{\mathrm{phonon}}\, d\omega.$$

Therefore, in the pure-intensity integration, phonon contributions are explicitly included along with charge-excitation contributions.

Absolute intensity maps at 21K, 62K, 104K, and 155K.

1D cuts of absolute intensity versus energy loss, color-coded by (H - 0.24).

Energy-integrated pure intensity using energy loss > 10 meV. Left: integrated intensity versus (H - 0.24) at all temperatures. Right: integrated intensity versus temperature at selected momentum values.

Because this is not a subtraction analysis, the integrated quantity contains both charge and phonon contributions in the selected energy window.

As a simple phonon-reference test, we also define a momentum-referenced quantity:

$$\Delta I_{\mathrm{int}}(H,T) = I_{\mathrm{int}}(H,T) - I_{\mathrm{int}}(H_{\mathrm{ref}},T), \quad H_{\mathrm{ref}}=0.15.$$

If H=0.15 is phonon-dominated and the phonon intensity is approximately momentum-independent over the selected H range, this subtraction can suppress much of the phonon background and better isolate the momentum-dependent component.