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.
Susceptibility is a measure of how easily a material can become magnetized in the presence of an external magnetic field. The imaginary part being equal to 0 means that the material is not affected by the magnetic field in terms of its ability to become magnetized.
A material with susceptibility's imaginary part = 0 behaves as if it is not influenced by the magnetic field. This means that it will not exhibit any magnetic properties, such as being attracted or repelled by a magnet.
The imaginary part of susceptibility can be equal to 0 due to a few factors. One possible reason is that the material is not capable of being magnetized, such as non-magnetic materials like plastic or wood. Another reason could be that the material is at a temperature above its Curie temperature, where it loses its magnetic properties.
No, a material with susceptibility's imaginary part = 0 is not considered to be magnetic. This is because the material does not exhibit any magnetic properties and is not affected by the presence of a magnetic field.
The real part of susceptibility, also known as the susceptibility's susceptibility's real part, is related to the imaginary part by the Kramers-Kronig relations. These relations describe the mathematical relationship between the real and imaginary parts of a complex function, such as susceptibility. In the case of susceptibility, the real and imaginary parts are inversely related, meaning that as one increases, the other decreases.