Deconfinement of spinons on critical points: MultiflavorCP1+U(1)lattice gauge theory in three dimensions
| Autor: | Ikuo Ichinose, Shunsuke Takashima, Tetsuo Matsui |
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| Rok vydání: | 2006 |
| Předmět: | |
| Zdroj: | Physical Review B. 73 |
| ISSN: | 1550-235X 1098-0121 |
| DOI: | 10.1103/physrevb.73.075119 |
| Popis: | In this paper, we study the three-dimensional ${N}_{\mathrm{f}}$-flavor ${\mathrm{CP}}^{1}$ model (a set of ${N}_{\mathrm{f}}$ ${\mathrm{CP}}^{1}$ variables) coupled with a dynamical compact U(1) gauge field by means of Monte Carlo simulations. This model is relevant to two-dimensional $s=\frac{1}{2}$ quantum spin models, and has a phase transition line which separates an ordered phase of global spin symmetry from a disordered one. From a gauge theoretical point of view, the ordered phase is a Higgs phase whereas the disordered phase is a confinement phase. We are interested in the gauge dynamics just on the critical line, in particular, whether a Coulomb-like deconfinement phase is realized there. This problem is quite important to clarify low-energy excitations in certain class of quantum spin models. If the gauge dynamics is in the deconfinement phase there, spinons, which transform in the fundamental representation of the $\mathrm{SU}({N}_{\mathrm{f}})$ symmetry, appear as low-energy excitations. By Monte Carlo simulations, we found that the ``phase structure'' on the criticality strongly depends on the value of ${N}_{\mathrm{f}}$. For small ${N}_{\mathrm{f}}$, the confinement phase is realized, whereas the deconfinement phase appears for sufficient large ${N}_{\mathrm{f}}\ensuremath{\geqslant}14$. This result strongly suggests that compact ${\mathrm{QED}}_{3}$ is in a deconfinement phase for sufficiently large number of flavors of massless fermions. |
| Databáze: | OpenAIRE |
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