Listar Ciencias Exactas y Naturales por tema "Hamiltonianos de spin"

Mostrando ítems 1-4 de 4

    • Inverse transition in a two-dimensional dipolar frustrated ferromagnet 

      Cannas, Sergio A.; Carubelli, Marianela; Billoni, Orlando Vito; Stariolo, Daniel Adrian (2011) [Artículo de periódico]
      We show that the mean-field phase diagram of the dipolar frustrated ferromagnet in an external field presents an inverse transition in the field-temperature plane. The presence of this type of transition has recently been ...

    • Magnetic and orbital ordering of RuO/sub 2/ planes in RuSr/sub 2/ (Eu,Gd) Cu/sub 2/O/sub 8/ 

      Aligia, Armando A.; Gusmao, Miguel Angelo Cavalheiro (2004) [Artículo de periódico]
      We start from an effective Hamiltonian for Ru ions in a square lattice, which includes the on-site interactions between t2g orbitals derived from Coulomb repulsion, and a tetragonal crystal-field splitting. Using perturbation ...

    • Nematic phase in two-dimensional frustrated systems with power-law decaying interactions 

      Barci, Daniel G.; Ribeiro, Leonardo Rodrigues; Stariolo, Daniel Adrian (2013) [Artículo de periódico]
      We address the problem of orientational order in frustrated interaction systems as a function of the relative range of the competing interactions. We study a spin model Hamiltonian with short-range ferromagnetic interaction ...

    • Realizing time crystals in discrete quantum few-body systems 

      Barfknecht, Rafael Emilio; Rasmussen, Stig Elkjær; Foerster, Angela; Zinner, Nikolaj Thomas (2019) [Artículo de periódico]
      The exotic phenomenon of time-translation-symmetry breaking under periodic driving—one of the main features of the so-called time crystals—has been shown to occur in many-body systems even in clean setups where disorder ...