Searching for room temperature ferromagnetic semiconductors has evolved into a broad field of material science and spintronics decades, nevertheless, these novel states remain rare. Phosphorene, monolayer black phosphorus with puckered honeycomb lattice structure possessing finite band gap high carrier mobility, been synthesized recently. Here we show, by means two different large scale quantum Monte-Carlo methods, that relatively weak interactions can lead to remarkable edge magnetism in...

A partial charge-spin separation fermion-spin theory is developed to study the normal-state properties of underdoped cuprates.In this approach, physical electron decoupled as a gauge invariant dressed holon and spinon, with behaving like spinful fermion, representing charge degree freedom together phase part spin freedom, while spinon hard-core boson, amplitude freedom.The local constraint for single occupancy satisfied.Within dynamics cuprates are studied based on t-t ′ -J model.It shown...

To address the issue of electron correlation driven superconductivity in graphene, we perform a systematic quantum Monte Carlo study pairing $t\ensuremath{-}U\ensuremath{-}V$ Hubbard model on honeycomb lattice. For $V=0$ and close to half filling, find that with $d+id$ (${d}_{{x}^{2}\ensuremath{-}{y}^{2}}+i{d}_{xy}^{\ensuremath{'}}$ its specific form) symmetry dominates extended-$s$ symmetry. However, as system size or on-site Coulomb interaction increases, long-range part decreases tends...

We have studied the electronic properties in aperiodic graphene superlattices of Thue-Morse sequence. Although structure is aperiodic, an unusual Dirac point (DP) does exist and its location exactly at energy corresponding to zero-averaged wave number (zero-k¯). Furthermore, zero-k¯ gap associated with DP robust against lattice constants incident angles, multi-DPs may appear under suitable conditions. A resultant controllability transport sequence predicted, which facilitate development many...

We used a quantum Monte Carlo method to study the magnetic impurity adatoms on graphene. found that by tuning chemical potential we could switch values of impurity's local magnet moment between relatively large and small values. Our computations spectral density its behavior differ significantly from an in normal metal our charge-charge spin-spin correlations conduction band electrons them be strongly suppressed. In general results are consistent with those poor man's scaling numerical...

We study the Hubbard model on honeycomb lattice with nearest-neighbor hopping $(t>0)$ and next-nearest-neighbor $({t}^{\ensuremath{'}}<0)$. When ${t}^{\ensuremath{'}}<\ensuremath{-}t/6$, single-particle spectrum is featured by continuously distributed Van Hove saddle points at band bottom, where density of states diverges in a power law. investigate possible unconventional superconductivity such systems Fermi level close to bottom employing both random-phase-approximation determinant quantum...

By using the constrained-phase quantum Monte Carlo method, we performed a systematic study of ground state half filled Hubbard model for trilayer honeycomb lattice. We analyze effect perpendicular electric field on electronic structure, magnetic property and pairing correlations. It is found that antiferromagnetism suppressed by field, especially long-range parts, dominant fluctuations are still antiferromagnetic. The correlation drives $d+id$ superconducting to be over other patterns among...

We perform a systematic quantum Monte Carlo study of the pairing correlation in ${S}_{4}$ symmetric microscopic model for iron-based superconductors. It is found that with an extensive $s$-wave symmetry robustly dominates over other pairings at low temperature reasonable parameter region regardless change Fermi surface topologies. The susceptibility, effective interaction, and ($\ensuremath{\pi}$, 0) antiferromagnetic strongly increase as on-site Coulomb interaction increases, indicating...

We study the temperature dependent magnetic susceptibility of a strained graphene quantum dot by using determinant Monte Carlo method. Within Hubbard model on honeycomb lattice, our unbiased numerical results show that relative small interaction $U$ may lead to edge ferromagnetic like behavior in dot, and possible room transition is suggested. Around half filling, fluctuations at zigzag strengthened both markedly on-site Coulomb strain, especially low region. The resultant strongly enhanced...

This study introduces an innovative application of Physics-Informed Neural Networks (PINN) for regression-based prediction the Air-Entry Value (AEV) in unsaturated soils, offering a novel approach to predicting soil hydraulic properties crucial understanding water movement, rainfall infiltration, and groundwater recharge hydrology engineering geology. AEV, critical parameter migration, significantly influences processes such as erosion, surface runoff, landslide initiation, recharge. For...

Within a Hubbard model, we investigate the superconducting pairing behavior of infinite-layer nickelate NdNiO2 and cuprate superconductors by using determinant quantum Monte Carlo method. Our focus is on comparing their dominant symmetries. The results indicate that dx2−y2 interaction significantly enhanced at low temperatures in both doped nickelates cuprates, whereas other typical symmetries are effectively suppressed, highlighting dominance form. Additionally, find effective for slightly...

We study spontaneous symmetry breakings for fermions (spinless and spinful) on a two-dimensional kagome lattice with nearest-neighbor repulsive interactions in weak coupling limit, focus particular topological Mott insulator instability. It is found that at $\frac{1}{3}$-filling where there quadratic band crossing $\ensuremath{\Gamma}$-point, agreement K. Sun, H. Yao, E. Fradkin, S. Kivelson, Phys. Rev. Lett. 103, 046811 (2009), the instabilities are infinitesimal phases dynamically...

We systematically study magnetic correlations in graphene within Hubbard model on a honeycomb lattice by using quantum Monte Carlo simulations. In the filling region below Van Hove singularity, system shows short-range ferromagnetic correlation, which is slightly strengthened on-site Coulomb interaction and markedly next-nearest-neighbor hopping integral. The properties depend electron strongly, may be manipulated electric gate. Due to its resultant controllability of ferromagnetism,...

We study the effect of disorder on semimetal -- Mott insulator transition in half-filled repulsive Hubbard model a honeycomb lattice, system that features vanishing density states at Fermi level. Using determinant quantum Monte Carlo method, we characterize various phases terms bulk-limit antiferromagnetic (AF) order parameter, compressibility, and temperature-dependent DC conductivity. In clean limit, our data are consistent with previous results showing single critical point separating...

Motivated by the recently experimental reported signatures of tunable Mott insulating state and superconductivity in an ABC graphene trilayer superlattice, we investigate charge compressibility, spin correlation, superconducting instability within Hubbard model on a three-layer honeycomb lattice. It is found that antiferromagnetically ordered insulator emerges beyond critical $U_c$ at half-filling, electronic correlation drives $d+id$ pairing to be dominant over other patterns wide doped...

Most recently, a phosphorus allotrope called green has been predicted, which direct bandgap up to 2.4 eV, and its single-layer form termed phosphorene shows high stability. Here, the mechanical properties uniaxial strain effect on electronic band structure of along two perpendicular in-plane directions were investigated. Remarkably, we found that this material can sustain tensile in armchair direction threshold 35% is larger than black phosphorene, suggesting more puckered. Our calculations...

Motivated by recent experimental studies that have found signatures of a correlated insulator phase and tuning superconductivity in twisted bilayer graphene, we study the temperature-dependent conductivity, spin correlation, superconducting pairing correlation within two-orbital Hubbard model on an emergent honeycomb lattice. The evaluation temperature dependence conductivity demonstrates there is metal-insulator transition Mott at strong coupling accompanied antiferromagnetic order....

We investigate electronic band structure and transport properties in bilayer graphene superlattices of Thue-Morse sequence. It is interesting to find that the zero-k¯ gap center sensitive interlayer coupling t′, centers all gaps shift versus t′ at a linear way. Extra Dirac points may emerge ky≠0, when extra are generated pairs, conductance obeys diffusive law, Fano factor tends be 1/3 as order sequence increases. Our results provide flexible effective way control graphene.

Understanding the relationship between stripe order and other phenomena, including antiferromagnetism superconductivity, is one of central issues in cuprate superconductors. The discovery that similar phase diagram exhibits both hole-doped electron-doped cuprates brings a chance to explore subtle role plays mechanism superconductivity. To investigate this question, we study behavior superconducting pairing interaction within an inhomogeneous Hubbard model by quantum Monte Carlo method. Our...

By using the constrained-phase quantum Monte Carlo method, we performed a systematic study of pairing correlations in ground state doped Kane-Mele-Hubbard model on honeycomb lattice. We find that with $d+id$ symmetry dominate close to half filling, but $p+ip$ as hole doping moves system below three-quarters filling. correlate these behaviors topology Fermi surfaces non-interacting problem. also effective correlation is enhanced greatly interaction increases, and superconducting are robust...

Abstract We reveal an edge spin triplet p- wave superconducting pairing correlation in slightly doped zigzag graphene nanoribbons. By employing a method that combines random-phase approximation, the finite-temperature determinant quantum Monte Carlo approach, and ground-state constrained-path method, it is shown such spin-triplet mediated by ferromagnetic fluctuations caused flat band at edge. The susceptibility effective interactions strongly increase as on-site Coulomb interaction...

Motivated by recent experimental studies on superconductivity found in nickelate-based materials, we study the temperature dependence of spin correlation and superconducting pairing interaction within an effective two-band Hubbard model quantum Monte Carlo method. Based parameters extracted from first-principles calculations, our intensive numerical results reveal that with a ${d}_{xy}$-wave symmetry firmly dominates over other pairings at low temperature, which is mainly determined Ni $3d$...

We develop a partial charge-spin separation fermion-spin theory implemented by the gauge invariant dressed holon and spinon. In this novel approach, physical electron is decoupled as spinon, with behaviors like spinful fermion, represents charge degree of freedom together phase part spin freedom, while spinon hard-core boson, amplitude then single occupancy local constraint satisfied. Within transport response underdoped cuprates studied. It shown that mainly governed scattering from holons...