Computer Simulation of a Magnetized Two-Dimensional System

Christian F. Roos

Alessandro Sfondrini, Javier Cerrillo, Norbert Schuch +1 more

Simulating frustrated quantum magnets is among the most challenging tasks in computational physics. We apply string-bond states, a recently introduced Ansatz which combines tensor networks with Monte Carlo based methods to the simulation of frustrated quantum systems in both two and three dimensions. We compare our results with existing results for unfrustrated and two-dimensional systems with open boundary conditions and demonstrate that the method applies equally well to the simulation of frustrated systems with periodic boundaries in both two and three dimensions.

Djordje Spasojević, Sanja Janićević

J. Stajic

Quantum Simulation Strongly interacting quantum systems present a challenge to computational methods even at a relatively low particle number of a few dozen. Researchers are looking to tackle such problems by simulating them in a well-understood and controllable system. A linear array of ions is one such system; however, assembling a large enough number of ions is tricky. Bohnet et al. show that a two-dimensional “crystal” of around 200 9Be+ ions held together by magnetic and electric fields in a so-called Penning trap can simulate quantum magnetism. The work sets the stage for simulations with more complicated forms of interaction that classical computers would find intractable. Science , this issue p. [1297][1] [1]: /lookup/doi/10.1126/science.aad9958

Takeshi Takahashi, M Shimizu

A computer simulation on the dilute Ising ferromagnet, where the magnetic atoms are distributed randomly in a two-dimensional matrix of non-magnetic atoms, is carried out. The interaction between the magnetic atoms is assumed to be long range. The numerical results for the temperature dependence of the magnetic specific heat show broad and round peaks. This rounding is too large to be attributed to the small size of the system. It is concluded that most of the rounding can be attributed to the spatial distribution of the local field due to the random distribution of the magnetic atoms. On the other hand, the results for the magnetic susceptibility show rather sharp peaks.

Michael J. Creutz, P. Mitra, Kevin J. M. Moriarty