Excitaci

Excitaci is a term used in several languages to denote the process or state of excitation—the introduction of energy to a system that raises it from a lower energy state to a higher one.

In physics and chemistry, excitation refers to promoting electrons, vibrational modes, or rotational modes to higher energy levels. Electronic excitation occurs when atoms or molecules absorb photons or collide with energetic particles; vibrational and rotational excitations involve changes in molecular motion. The immediate result is often a short-lived excited state, followed by de-excitation through emission of light (fluorescence or phosphorescence) or energy transfer to other modes or surroundings. Electronic excitations are central to spectroscopy, photovoltaics, and light emission technologies.

In solid-state physics, excitations include electron-hole pairs in semiconductors, plasmons, and excitons, whose properties influence the behavior of devices such as LEDs, solar cells, and lasers. In condensed matter, lattice excitations (phonons) play a major role in thermal conductivity and phase transitions.

In biology and neuroscience, excitaci is used to describe neuronal or cellular excitability—the ability of a cell to respond to stimuli and propagate signals, such as action potentials in nerve cells.

In engineering, excitation refers to the input signal or current that drives a device, actuator, or sensor, shaping its response. Examination of excitaci often involves spectroscopy, luminescence measurements, or time-resolved techniques to study lifetimes and transition probabilities.