Tensor-product state approach to spin-1/2 square J(1)-J(2) antiferromagnetic Heisenberg model

Autor(en)

Ling Wang, Zheng-Cheng Gu, Frank Verstraete, Xiao-Gang Wen

Abstrakt

The ground state phase of a spin-1/2 J(1)-J(2) antiferromagnetic Heisenberg model on a square lattice around the maximally frustrated regime (J(2) similar to 0.5J(1)) has been debated for decades. Here we study this model using the cluster update algorithm for tensor-product states (TPSs). The ground state energies at finite sizes and in the thermodynamic limit (with finite size scaling) are in good agreement with exact diagonalization study. Through finite size scaling of the spin correlation function, we find the critical point J(2)(c1) = 0.572(5) J(1) and critical exponents nu = 0.50(8), eta(s) = 0.28(6). In the range of 0.572 <J(2)/J(1) <= 0.6 we find a paramagnetic ground state with an exponentially decaying spin-spin correlation. Up to a 24x24 system size, we observe power law decaying dimer-dimer and plaquette-plaquette correlations with an anomalous plaquette scaling exponent eta(p) = 0.24(1) and an anomalous columnar scaling exponent eta(c) = 0.28(1) at J(2)/J(1) = 0.6. These results are consistent with a potential gapless U(1) spin-liquid phase. However, since the U(1) spin liquid is unstable due to the instanton effect, a valence bond solid order with very small amplitude might develop in the thermodynamic limit. Thus, our numerical results strongly indicate a deconfined quantum critical point at J(2)(c1). Remarkably, all the observed critical exponents are consistent with the J-Q model.

Organisation(en)

Quantenoptik, Quantennanophysik und Quanteninformation

Externe Organisation(en)

Chinese Academy of Sciences (CAS), California Institute of Technology (Caltech), Chinese University of Hong Kong, Perimeter Institute for Theoretical Physics, Ghent University , Massachusetts Institute of Technology

Journal

Physical Review B

Band

94

Anzahl der Seiten

6

ISSN

1098-0121

DOI

https://doi.org/10.1103/PhysRevB.94.075143

Publikationsdatum

08-2016

Peer-reviewed

Ja

ÖFOS 2012

103015 Kondensierte Materie

Schlagwörter

ASJC Scopus Sachgebiete

Electronic, Optical and Magnetic Materials, Condensed Matter Physics

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/12f680eb-dca3-43bc-82c1-52fafac1a5f7