Yes, elementary particles are considered quantum entities. In the framework of quantum mechanics, elementary particles are described by wave functions that exhibit quantum behavior.
Quantum mechanics provides a mathematical framework to describe the behavior of particles at the microscopic scale, including elementary particles. According to quantum mechanics, particles such as electrons, quarks, and photons are treated as quantum objects, meaning they exhibit wave-particle duality. This duality implies that particles can exhibit both particle-like and wave-like properties depending on the experimental setup.
Elementary particles are subject to the principles of quantum mechanics, including superposition, uncertainty principle, and quantization. They can exist in superposition states, where they can simultaneously exist in multiple states until observed or measured. The uncertainty principle states that there are inherent limits to the precision with which certain pairs of physical properties, such as position and momentum, can be known simultaneously. Additionally, the energy levels and properties of elementary particles are quantized, meaning they can only take certain discrete values.
The behavior of elementary particles, as described by quantum mechanics, has been extensively tested and validated through experimental observations and theoretical calculations. Quantum field theory, which combines quantum mechanics and special relativity, is used to describe the behavior of elementary particles and their interactions.
So, in summary, elementary particles are considered quantum entities because their behavior and properties are governed by the principles and mathematics of quantum mechanics.