motrunich Science Dirac composite fermions

Two-dimensional momentum space view of density-density correlations. See Fig 2 in publication for full caption

A recent Science article features work by IQIM alums Scott Geraedts and Roger Mong, and Professor of Theoretical Physics Lesik Motrunich with collaborators.  From Science: “All is well with particle-hole symmetry In an external magnetic field, the energy of an electron in a two-dimensional system takes discrete values, called Landau levels. At high enough fields, all electrons in a solid can fit in the lowest Landau level. If exactly half of that level is filled with electrons, standard theory predicts that a special fermion liquid phase will form that makes a distinction between the filled and empty states (particles and holes). A recent conjecture, in contrast, predicted a liquid consisting of massless Dirac particles that respects the symmetry between particles and holes. Geraedts et al. used sophisticated numerical methods to provide strong evidence for this conjecture.” Read the full article,   Scott D. Geraedts, Michael P. Zaletel, Roger S. K. Mong, Max A. Metlitski, Ashvin Vishwanath, Olexei I. Motrunich, The half-filled Landau level: The case for Dirac composite fermions,  Science 08 Apr 2016:Vol. 352, Issue 6282, pp. 197-201, DOI: 10.1126/science.aad4302