Exploring the many-body localization transition in two dimensions
  One fundamental assumption in statistical physics is that generic closed quantum many-body systems thermalize under their own dynamics. Recently, the emergence of many-body localized systems has questioned this concept, challenging our understanding of the connection between statistical physics and quantum mechanics. Here we report on the observation of a many-body localization transition between thermal and localized phases for bosons in a two-dimensional disordered optical lattice. With our single site resolved measurements we track the relaxation dynamics of an initially prepared out-of-equilibrium density pattern and find strong evidence for a diverging length scale when approaching the localization transition. Our experiments mark the first demonstration and in-depth characterization of many-body localization in a regime not accessible with state-of-the-art simulations on classical computers. 
Jae-yoon Choi, Sebastian Hild, Johannes Zeiher, Peter Schau{\ss},   Antonio Rubio-Abadal, Tarik Yefsah, Vedika Khemani, Davi...
cond-mat.quant-gas cond-mat.dis-nn cond-mat.stat-mech cond-mat.str-el