Transverse depinning threshold revealed by non linear Hall effect of Wigner solid in a disorder field F.I.B. Williams, F. Perruchot, B. Etienne, C.J. Mellor, R. Gaal, B. Sas, M. Hannini, T. Foxon et J. Harris J. Phys. IV France, 12 9 (2002) 329 DOI: 10.1051/jp4:20020430