Quantum electrodynamics in 2+1 dimensions with quenched disorder: Quantum critical states with interactions and disorder

Article

关键词: GROUND-STATES;    VALENCE-BOND;    SPIN-PEIERLS;   

DOI  :  10.1103/PhysRevB.95.235146

来源: SCIE

【 摘 要 】

Quantum electrodynamics in 2+1 dimensions (QED(3)) is a strongly coupled conformal field theory (CFT) of a U(1) gauge field coupled to 2N two-component massless fermions. The N = 2 CFT has been proposed as a ground state of the spin-1/2 kagome Heisenberg antiferromagnet. We study QED3 in the presence of weak quenched disorder in its two spatial directions. When the disorder explicitly breaks the fermion flavor symmetry from SU(2N) -> U(1) x SU(N) but preserves time-reversal symmetry, we find that the theory flows to a nontrivial fixed line at nonzero disorder with a continuously varying dynamical critical exponent z > 1. We determine the zero-temperature flavor (spin) conductivity along the critical line. Our calculations are performed in the large-N limit, and the disorder is handled using the replica method.

【 授权许可】

Free