Quantum phase transition and criticality in quasi-one-dimensional spinless Dirac fermions

Article

关键词: CRITICAL EXPONENTS;    LIQUID;    MODEL;   

DOI  :  10.1103/PhysRevB.100.125145

来源: SCIE

【 摘 要 】

We study the quantum criticality of spinless fermions on a quasi-one-dimensional pi-flux square lattice in cylinder geometry, by using the infinite density matrix renormalization group and Abelian bosonization. For a series of cylinder circumferences L-y = 4n + 2 = 2, 6, ... with a periodic boundary condition, there are quantum phase transitions from gapped Dirac fermion states to charge density wave (CDW) states. We find that the quantum phase transitions for such circumferences are continuous and belong to the (1+1)-dimensional Ising universality class. On the other hand, when L-y = 4n = 4, 8, ..., there are gapless Dirac fermions at the noninteracting point and the phase transition to the CDW state is Gaussian. Both of these criticalities are described in a unified way by bosonization. We clarify their intimate relationship and demonstrate that a central charge c = 1/2 Ising transition line arises as a critical state of an emergent Majorana fermion from the c = 2 Gaussian transition point.

【 授权许可】

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