A vector quantity that allows Ampère's law to be written in terms of free current density alone as
in a dielectric having a bound current density
where M is the magnetization. Some authors call H the "magnetic field," and then invent a new term, the "magnetic induction," for the field B. Not only is this practice unnecessarily confusing, but the use of the term "induction" in this context is inconsistent with the much more widespread use of this word in electrodynamics. In fact, Sommerfeld (1952, p. 45) opines that "The unhappy term 'magnetic field' for H should be avoided as far as possible. It seems to us that this term has led into error none less than Maxwell himself." It is therefore best to simply refer to the field as "H," or, when necessary for clarity, the "auxiliary magnetic field" (Griffiths 1987, p. 230).
B, D, Bound Current Density, Free Current Density, Landau-Lifschitz-Gilbert Equation
References
Griffiths, D. J. "The Auxiliary Field H." §6.3 in Introduction to Electrodynamics, 3rd ed. Englewood Cliffs, NJ: Prentice-Hall, pp. 230-230, 1998.
