Field induced phase transition in the few photon regimeA. D. Panferov, S. A. Smolyansky, A. I. Titov, B. Kämpfer, A. Otto, D. B. Blaschke and L. JuchnowskiEPJ Web Conf., 138 (2017) 07004DOI: https://doi.org/10.1051/epjconf/201713807004