title: Two-dimensional melting: from liquid-hexatic coexistence to continuous transitions.
abstract: The phase diagram of two-dimensional continuous particle systems is studied using the event-chain Monte Carlo algorithm. For soft disks with repulsive power-law interactions ∝r^{-n} with n≳6, the recently established hard-disk melting scenario (n→∞) holds: a first-order liquid-hexatic and a continuous hexatic-solid transition are identified. Close to n=6, the coexisting liquid exhibits very long orientational correlations, and positional correlations in the hexatic are extremely short. For n≲6, the liquid-hexatic transition is continuous, with correlations consistent with the Kosterlitz-Thouless-Halperin-Nelson-Young (KTHNY) scenario. To illustrate the generality of these results, we demonstrate that Yukawa particles likewise may follow either the KTHNY or the hard-disk melting scenario, depending on the Debye-Hückel screening length as well as on the temperature.
authors: Laboratoire de Physique Statistique, Ecole Normale Supérieure, UPMC, Université Paris Diderot, CNRS, 24 rue Lhomond, 75005 Paris, France.
authors: Sebastian C
authors: SC
authors: Kapfer
authors: Laboratoire de Physique Statistique, Ecole Normale Supérieure, UPMC, Université Paris Diderot, CNRS, 24 rue Lhomond, 75005 Paris, France.
authors: Werner
authors: W
authors: Krauth