Frustration-induced quantum spin liquid behavior in the s = 1=2 Random-bond Heisenberg antiferromagnet on the Zigzag Chain

Abstract

Recent studies have revealed that the randomness-induced quantum spin liquid (QSL)-like state is stabilized in certain frustrated quantum magnets in two and three dimensions. In order to clarify the nature of this gapless QSL-like state, we investigate both zero- and finite-temperature properties of the random-bond one-dimensional (1D) s = 1=2 Heisenberg model with the competing nearest-neighbor and next-nearest-neighbor antiferromagnetic interactions, J1 and J2, by means of the exact diagonalization, density-matrix renormalization-group and Hams-de Raedt methods. We find that, on increasing the frustration J2, the gapless nonmagnetic state stabilized in the unfrustrated model with J2 = 0, the unfrustrated random-singlet (RS) state, exhibits a phase transition into different gapless nonmagnetic state, the frustrated RS state. This frustrated RS state in 1D has properties quite similar to the randomness-induced QSL-like state recently identified in 2D and 3D frustrated magnets exhibiting the T-linear low-temperature (T) specific heat, while the unfrustrated RS state is more or less specific to the unfrustrated 1D system exhibiting the ∼1=∣log T ∣3 low-T specific heat. Universal features and the robustness against perturbations of the frustrated RS state are emphasized.