Liquid crystalline states for two-dimensional electrons in strong magnetic fields

Based on the Kosterlitz-Thouless-Halperin-Nelson- Young (KTHNY) theory of two-dimensional melting and the analogy between Laughlin states and the two- dimensional one-component plasma (2DOCP), we investigate the possibility of liquid crystalline states in a single Landau level (LL). We introduce many-body trial wavefunctions that are translationally invariant but posess 2-fold (i.e. nematic ), 4-fold (tetratic) or 6-fold (hexatic) broken rotational symmetry at respective filling factors nu = 1/3, 1/5 and 1/7 of the valence LL. We find that the above liquid crystalline states exhibit a soft charge density wave (CDW) which underlies the translationally invariant state but which is destroyed by quantum fluctuations. By means of Monte Carlo (MC) simulations, we determine that, for a considerable variety of interaction potentials, the anisotropic states are energetically unfavorable for the lowest and first excited LL's (with inde XL = 0, 1), whereas the nematic is favorable at the second excited LL (L = 2).