  There is a considerable amount of work that shows the biomagnetism of organic
components without ferromagnetic components at the molecular level, but it is
of great challenge to cover the giant gap of biomagnetism between their
experimental and theoretical results. Here, we show that the diamagnetism of an
aromatic peptide, the AYFFF, is greatly enhanced for about 11 times by
self-assembling, reaching two orders of magnitude higher than the mass
susceptibility of pure water. Moreover, the AYFFF self-assemblies further mixed
with ZnCl2 solution of sufficiently high concentrations display
superparamagnetism, with the mass susceptibility reaching more than two orders
of magnitude higher than the absolute value of pure water, which may approach
the mass susceptibility of ferromagnetism. The aromatic rings in the peptide
molecules and the cations are the keys to such a strong diamagnetism and
superparamagnetism of aromatic peptides.
