A plasmon is defined as any decimal amount of physical entity taking part in an interaction. The process of interaction is referred to as quantum, where free electrons are in constant motion. During the quantum process, electrons are rapidly moved from one point to the other to bring about plasma oscillations. An oscillation is what leads to plasmon, which entails the unstable state of the dielectric function of any gas that is in motion. Therefore, a plasmon is a quantisation process involving all systems of oscillations.
Volume plasmon is, therefore, the quantisation of the longitudinal ions inside an electron gas, usually referred to as plasma. Volume plasmon has higher energy compared to a surface plasmon. Oscillation processes take place between the interfaces of any existing material. Examples of such an interface include a metal-dielectric interface.
The difference between volume and surface plasmon is the amount of energy contained in the two systems. The former has lower energy compared to the latter, and that is why it is called volume plasmon.
Bibliography
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