Quadrupolar quantum criticality on a fractal

Abstract

We study the ground state ordering of quadrupolar ordered $S=1$ magnets as a function of spin dilution probability $p$ on the triangular lattice. In sharp contrast to the ordering of $S=1/2$ dipolar Néel magnets on percolating clusters, we find that the quadrupolar magnets are quantum disordered at the percolation threshold, $p=p^{\ast }$. Further we find that long-range quadrupolar order is present for all $p<p^{\ast }$ and vanishes first exactly at $p^{\ast }$. Strong evidence for scaling behavior close to $p^{\ast }$ points to an unusual quantum criticality without fine tuning that arises from an interplay of quantum fluctuations and randomness.

References in corpus (8)

• The quadrupolar phases of the S=1 bilinear-biquadratic Heisenberg model on the triangular lattice
• Possible ferro-spin nematic order in NiGa2S4
• Quadrupolar correlations and spin freezing in S = 1 triangular lattice antiferromagnets
• Percolation quantum phase transitions in diluted magnets
• Quantum-criticality and percolation in dimer-diluted 2D antiferromagnets
• Spin nematic ground state of the triangular lattice S=1 biquadratic model
• Spin dynamics of the bilinear-biquadratic $S=1$ Heisenberg model on the triangular lattice: a quantum Monte Carlo study
• Ordering near the percolation threshold in models of 2D interacting bosons with quenched dilution