George BuLah (X) Apr 27, 2014:

@M.A.B. Wcześniej i potem masz...

As discussed in Section 1.2.1, zigzag graphene nanoribbons have so-called edge
states. According to numerous theoretical studies based on density functional theory
or on the mean-field Hubbard model, it is believed that the associated peak in
the density of states at the Fermi energy (EF) gives rise to a magnetic instability,
where the edge states become spin-polarized [22,103,104]. In the magnetic ground
state, a band gap at EF is opened, and the atoms are ferromagnetically ordered along
one edge, and antiferromagnetically ordered between opposite edges.

Całość, tu:
http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd...

M.A.B. Apr 27, 2014:

A co jest wcześniej? Bo ten peak jest pewnie associated with sth