No, electrons are not always in a coherent state. In quantum mechanics, a coherent state is a specific type of quantum state that exhibits certain properties, such as a well-defined phase and minimal uncertainty in both position and momentum. Coherent states are typically associated with classical-like behavior and are often used to describe laser light or certain types of quantum oscillators.
However, electrons in atoms and molecules generally do not exist in coherent states. Instead, their behavior is described by wavefunctions, which are superpositions of various quantum states. These wavefunctions can exhibit interference effects, such as those observed in electron diffraction experiments, but they do not necessarily correspond to coherent states.
It's worth noting that the concept of coherence is more commonly applied to light or other bosonic systems, rather than fermionic systems like electrons. In the context of electrons, terms like "coherent transport" or "coherent scattering" may be used, but they refer to the coherent behavior of the system as a whole, rather than the individual electrons themselves being in coherent states.