At low temperature and under weak magnetic field, non-interacting Fermi gases reveal both Pauli paramagnetism and Landau diamagnetism, and the magnitude of the diamagnetic susceptibility is 1/3 of that of the paramagnetic one. When the temperature is finite and the magnetic field is also finite, we demonstrate that the paramagnetism and diamagnetism start to deviate from the ratio 1/3. For understanding the magnetic properties of an ideal Fermi gas at quite low temperature and under quite weak magnetic field, we work out explicitly the third-order magnetic susceptibility in three cases, from intrinsic spin, orbital motion and in total. An interesting property is in third-order magnetic susceptibilities:when viewing individually, they are both diamagnetic, but in total it is paramagnetic.
Long-Quan Lai, Zhao Li, Ya-Bin Yu, Quan-Hui Liu
. Third-Order Magnetic Susceptibility of an Ideal Fermi Gas[J]. Communications in Theoretical Physics, 2018
, 70(05)
: 619
-624
.
DOI: 10.1088/0253-6102/70/5/619
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