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Dapeng Hao

Publications and source records attributed to Dapeng Hao.

4 recordsLinked to original sources

Extended-range percolation in five dimensions

Percolation on a five-dimensional simple hypercubic (sc(5)) lattice with extended neighborhoods is investigated by means of extensive Monte Carlo simulations, using an effective single-cluster growth algorithm. The critical exponents, including $\tau$ and $\Omega$, the asymptotic behavior of the threshold $p_c$ and its dependence on coordination number $z$ are investigated. Using the bond and site percolation thresholds $p_c = 0.11817145(3)$ and $0.14079633(4)$ respectively given by Mertens and Moore [Phys. Rev. E 98, 022120 (2018)], we find critical exponents of $\tau = 2.4177(3)$, $\Omega = 0.27(2)$ through a self-consistent process. The value of $\tau$ compares favorably with a recent five-loop renormalization predictions $2.4175(2)$ by Borinsky et al. [Phys. Rev. D 103, 116024 (2021)], the value 2.4180(6) that follows from the work of Zhang et al. [Physica A 580, 126124 (2021)], and the measurement of $2.419(1)$ by Mertens and Moore. We also confirmed the bond threshold, finding $p_c = 0.11817150(5)$. sc(5) lattices with extended neighborhoods up to 7th nearest neighbors are studied for both bond and site percolation. Employing the values of $\tau$ and $\Omega$ mentioned above, thresholds are found to high precision. For bond percolation, the asymptotic value of $zp_c$ tends to Bethe-lattice behavior ($z p_c \sim 1$), and the finite-$z$ correction is found to be consistent with both and $zp_{c} - 1 \sim a_1 z^{-0.88}$ and $zp_{c} - 1 \sim a_0(3 + \ln z)/z$. For site percolation, the asymptotic analysis is close to the predicted behavior $zp_c \sim 32\eta_c = 1.742(2)$ for large $z$, where $\eta_c = 0.05443(7)$ is the continuum percolation threshold of five-dimensional hyperspheres given by Torquato and Jiao [J. Chem. Phys 137, 074106 (2015)]; finite-$z$ corrections are accounted for by taking $p_c \approx c/(z + b)$ with $c=1.722(7)$ and $b=1$.

cond-mat.stat-mech

Improved finite-difference and pseudospectral schemes for the Kardar-Parisi-Zhang equation with long-range temporal correlations

To investigate universal behavior and effects of long-range temporal correlations in kinetic roughening, we perform extensive simulations on the Kardar-Parisi-Zhang (KPZ) equation with temporally correlated noise based on pseudospectral (PS) and one of the improved finite-difference (FD) schemes. We find that scaling properties are affected by long-range temporal correlations within the effective temporally correlated regions. Our results are consistent with each other using these two independent numerical schemes, three characteristic roughness exponents (global roughness exponent $α$, local roughness exponent $α_{loc}$, and spectral roughness exponent $α_{s}$) are approximately equal within the small temporally correlated regime, and satisfy $α_{loc} \approx α<α_{s}$ for the large temporally correlated regime, and the difference between $α_{s}$ and $α$ increases with increasing the temporal correlation exponent $θ$. Our results also show that PS and the improved FD schemes could effectively suppress numerical instabilities in the temporally correlated KPZ growth equation. Furthermore, our investigations suggest that when the effects of long-range temporal correlation are present, the continuum and discrete growth systems do not belong to the same universality class with the same temporal correlation exponent.

cond-mat.stat-mech

Site and bond percolation on four-dimensional simple hypercubic lattices with extended neighborhoods

The asymptotic behavior of the percolation threshold $p_c$ and its dependence upon coordination number $z$ is investigated for both site and bond percolation on four-dimensional lattices with compact extended neighborhoods. Simple hypercubic lattices with neighborhoods up to 9th nearest neighbors are studied to high precision by means of Monte-Carlo simulations based upon a single-cluster growth algorithm. For site percolation, an asymptotic analysis confirms the predicted behavior $zp_c \sim 16 η_c = 2.086$ for large $z$, and finite-size corrections are accounted for by forms $p_c \sim 16 η_c/(z+b)$ and $p_c \sim 1- \exp(-16 η_c/z)$ where $η_c \approx 0.1304$ is the continuum percolation threshold of four-dimensional hyperspheres. For bond percolation, the finite-$z$ correction is found to be consistent with the prediction of Frei and Perkins, $zp_{c} - 1 \sim a_{1} (\ln z)/z$, although the behavior $zp_{c} - 1 \sim a_1 z^{-3/4}$ cannot be ruled out.

cond-mat.stat-mech

Site percolation on square and simple cubic lattices with extended neighborhoods and their continuum limit

By means of Monte Carlo simulations, we study long-range site percolation on square and simple cubic lattices with various combinations of nearest neighbors, up to the eighth neighbors for the square lattice and the ninth neighbors for the simple cubic lattice. We find precise thresholds for 23 systems using a single-cluster growth algorithm. Site percolation on lattices with compact neighborhoods can be mapped to problems of lattice percolation of extended shapes, such as disks and spheres, and the thresholds can be related to the continuum thresholds $η_c$ for objects of those shapes. This mapping implies $zp_{c} \sim 4 η_c = 4.51235$ in 2D and $zp_{c} \sim 8 η_c = 2.73512$ in 3D for large $z$ for circular and spherical neighborhoods respectively, where $z$ is the coordination number. Fitting our data to the form $p_c = c/(z+b)$ we find good agreement with $c = 2^d η_c$; the constant $b$ represents a finite-$z$ correction term. We also study power-law fits of the thresholds.

cond-mat.stat-mech