Abstract
We study a one-dimensional spin-chain interacting with long-range dipolar forces in the presence of a transverse magnetic field. The system exhibits a quantum critical point belonging to the two-dimensional Ising universality class, whose critical behavior is investigated using the nonperturbative density-matrix and functional renormalization group methods. Interestingly, we find that linear spin-wave theory predicts a magnon dispersion characterized by a logarithmic singularity in the magnon velocity for vanishing momenta, due to the peculiar behavior of dipole-dipole interactions in one dimension. However, in the vicinity of the critical point this logarithmically divergent term is renormalized to zero by the effects of quantum fluctuations, signaling the reemergence of scale invariance, in accordance with the Ising critical scenario.
| Original language | English |
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| Article number | 291 |
| Journal | A I P Conference Proceedings |
| Volume | 1485 |
| ISSN | 1551-7616 |
| Publication status | Published - 3 Oct 2011 |
| Externally published | Yes |