Matter fields near quantum critical point in (2+1)-dimensional U(1) gauge theory

Guo-Zhu Liu; Wei Li; Geng Cheng

doi:10.1016/j.nuclphysb.2009.09.004

paper

Matter fields near quantum critical point in (2+1)-dimensional U(1) gauge theory

arXiv:0901.2889 · doi:10.1016/j.nuclphysb.2009.09.004

Abstract

We study chiral phase transition and confinement of matter fields in (2+1)-dimensional U(1) gauge theory of massless Dirac fermions and scalar bosons. The vanishing scalar boson mass, $r = 0$ , defines a quantum critical point between the Higgs phase and the Coulomb phase. We consider only the critical point $r = 0$ and the Coulomb phase with $r > 0$ . The Dirac fermion acquires a dynamical mass when its flavor is less than certain critical value $N_{f}^{c}$ , which depends quantitatively on the flavor $N_{b}$ and the scalar boson mass $r$ . When $N_{f} < N_{f}^{c}$ , the matter fields carrying internal gauge charge are all confined if $r \neq = 0$ but are deconfined at the quantum critical point $r = 0$ . The system has distinct low-energy elementary excitations at the critical point $r = 0$ and in the Coulomb phase with $r \neq = 0$ . We calculate the specific heat and susceptibility of the system at $r = 0$ and $r \neq = 0$ , which can help to detect the quantum critical point and to judge whether dynamical fermion mass generation takes place.

18 pages, 5 figures

Matter fields near quantum critical point in (2+1)-dimensional U(1) gauge theory

Abstract

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