Yes. And the corollary is that you cannot achieve laser cooling of atoms with stimulated emission alone, you need spontaneous emission.Khashishi said:Does entropy increase during spontaneous emission?
The answer depends on what kind of entropy do you have in mind. Do you mean entropy of the total closed system, or entropy of the subsystem (e.g. atom and photon, but without environment)? If you mean the former, then von Neumann entropy does not change, and information is encoded in the entanglement with environment. If you mean the latter, then von Neumann entropy increases, provided that you describe the system with the mixed state without a projection to the measured state.Khashishi said:Does entropy increase during spontaneous emission?
If not, how is the information about the emitted photon mode encoded into the initial state of the atom (and/or environment)? If so, where does the extra information come from?
Spontaneous emission entropy is a physical phenomenon that occurs when an atom or molecule emits a photon without any external stimulation. This process leads to an increase in the entropy of the system, as energy is released in the form of radiation.
The second law of thermodynamics states that the total entropy of a closed system always increases over time. Spontaneous emission entropy is an example of this principle, as the release of energy through photon emission leads to an increase in the entropy of the system.
The rate of spontaneous emission entropy is affected by several factors, including the energy level of the emitting atom or molecule, the temperature of the system, and the density of states of the surrounding environment. Higher energy levels, higher temperatures, and a greater density of states all lead to a higher rate of spontaneous emission entropy.
In most cases, spontaneous emission entropy cannot be controlled or manipulated since it is a natural and random process. However, in certain situations, such as in lasers, the rate of spontaneous emission can be increased or decreased through external factors like temperature or electric fields.
Spontaneous emission entropy has several practical applications, including in the development of lasers and other light-emitting devices. It also plays a role in the cooling of atoms and molecules through the process of evaporative cooling. Additionally, understanding spontaneous emission entropy is crucial in fields such as quantum mechanics and thermodynamics.