The discussion centers on the physical significance of the imaginary part of susceptibility in a two-level system when it approaches zero. It is established that the imaginary part of susceptibility is directly related to absorption; therefore, when this value is zero or nearly zero, it indicates that there is minimal to no absorption occurring in the system. This phenomenon occurs at specific frequencies of the applied external field.
PREREQUISITESPhysicists, materials scientists, and researchers studying quantum systems and their interactions with external fields will benefit from this discussion.
KFC said:I am reading a paper on applying an external field on a two-level system. And it turns out that at some frequency (of the field), the imaginary part of the susceptibility become very close to zero. I wonder what's the physical significance when imaginary part of the susceptibility is ZERO?
Thanks.