Domain wall roughening in dipolar films in the presence of disorder.
We derive a low-energy Hamiltonian for the elastic energy of a Néel domain wall in a thin film with in-plane magnetization, where we consider the contribution of the long-range dipolar interaction beyond the quadratic approximation. We show that such a Hamiltonian is analogous to the Hamiltonian of a one-dimensional polaron in an external random potential. We use a replica variational method to compute the roughening exponent of the domain wall for the case of two-dimensional dipolar interactions.
Santos
Jaime E
JE
Hahn-Meitner Institut, Abteilung SF5, Glienicker Strasse 100, 14109 Berlin, Germany. santos@hmi.de
Frey
Erwin
E
Schwabl
Franz
F