1. Politecnico di Torino,Department of Electronics and Telecommunications,Torino,Italia
2. Institut für Grundlagen der Elektrotechnik und Elektronik, TU Dresden,Dresden,Germany
3. Peter Grünberg Institute, Forschungszentrum Jülich GmbH,Jülich,Germany
4. University of California, Berkeley,Department of Electrical Engineering and Computer Sciences,Berkeley,California,USA