D'Emidio Jonathan, Sandvik Anders W
Donostia International Physics Center, P. Manuel de Lardizabal 4, 20018 Donostia-San Sebastián, Spain.
Boston University, Department of Physics, 590 Commonwealth Avenue, Boston, Massachusetts 02215, USA.
Phys Rev Lett. 2024 Oct 18;133(16):166702. doi: 10.1103/PhysRevLett.133.166702.
We study the Rényi entanglement entropy (EE) of the two-dimensional J-Q model, the emblematic quantum spin model of deconfined criticality at the phase transition between antiferromagnetic and valence-bond-solid ground states. State-of-the-art quantum Monte Carlo calculations of the EE reveal critical corner contributions that scale logarithmically with the system size, with a coefficient in remarkable agreement with the form expected from a large-N conformal field theory with SO(N=5) symmetry. However, details of the bipartition of the lattice are crucial in order to observe this behavior. If the subsystem for the reduced density matrix does not properly accommodate valence-bond fluctuations, logarithmic contributions appear even for cornerless bipartitions. We here use a 45° tilted cut on the square lattice. Beyond supporting an SO(5) deconfined quantum critical point, our results for both the regular and tilted cuts demonstrate important microscopic aspects of the EE that are not captured by conformal field theory.
我们研究了二维J-Q模型的雷尼纠缠熵（EE），该模型是反铁磁基态与价键固态基态之间相变时无禁闭临界性的典型量子自旋模型。对EE进行的最先进的量子蒙特卡罗计算揭示了临界角贡献，其与系统大小呈对数比例缩放，其系数与具有SO(N = 5)对称性的大N共形场论预期的形式显著一致。然而，晶格二分的细节对于观察这种行为至关重要。如果用于约化密度矩阵的子系统不能适当地容纳价键涨落，那么即使对于无角二分，也会出现对数贡献。我们在此对正方形晶格使用45°倾斜切割。除了支持SO(5)无禁闭量子临界点之外，我们对常规切割和倾斜切割的结果都展示了EE的重要微观方面，而这是共形场论所无法捕捉到的。
