Related papers: Monolayer polar metals with large piezoelectricity…
Janus two-dimensional (2D) materials have attracted much attention due to possessing unique properties caused by their out-of-plane asymmetry, which have been achieved in many 2D families. In this work, the Janus monolayers are predicted in…
A two-dimensional (2D) material system with both piezoelectricity and ferromagnetic (FM) order, referred to as a 2D piezoelectric ferromagnetism (PFM), may open up unprecedented opportunities for intriguing physics. Inspired by…
The recently experimentally synthesized monolayer $\mathrm{MoSi_2N_4}$ and $\mathrm{WSi_2N_4}$ (\textcolor[rgb]{0.00,0.00,1.00}{Science 369, 670-674 (2020})) lack inversion symmetry, which allows them to become piezoelectric. In this work,…
The seminal experimental discovery of the remarkably stable MoSi$_2$N$_4$ monolayer has led to a handful of predicted magnetic two-dimensional (2D) materials in the MA$_2$Z$_4$ family (M = transition metals, A = Si, Ge, and Z = N, P, As).…
Multifunctional two-dimensional (2D) multiferroics are promising materials for designing low-dimensional multipurpose devices. The key to multifunctionality in these materials is breaking the space-inversion and the time-reversal symmetry,…
Chemical vapor deposition has been most recently employed to fabricate centimeter-scale high-quality single-layer MoSi2N4 (Science; 2020;369; 670). Motivated by this exciting experimental advance, herein we conduct extensive…
Motived by experimentally synthesized $\mathrm{MoSi_2N_4}$ (\textcolor[rgb]{0.00,0.00,1.00}{Science 369, 670-674 (2020})), the intrinsic piezoelectricity in monolayer $\mathrm{XSi_2N_4}$ (X=Ti, Zr, Hf, Cr, Mo and W) are studied by density…
Sliding ferroelectricity is emerging as a distinct and promising mechanism for realizing ferroelectricity in low-dimensional systems, offering new design principles beyond the conventional ferroelectric mechanism. Further, the coexistence…
Recent discovery of ultrathick $\mathrm{MoSi_2N_4(MoN)_n}$ monolayers open up an exciting platform to engineer 2D material properties via intercalation architecture. Here we computationally investigate a series of ultrathick…
Very recently, the two-dimensional (2D) form of MoSi2N4 has been successfully fabricated [Hong et al., Sci. 369, 670 (2020)]. Motivated by theses recent experimental results, herein we investigate the structural, mechanical, thermal,…
Two-dimensional (2D) materials with nodal-loop band crossing have been attracting great research interest. However, it remains a challenge to find 2D nodal loops that are robust against spin-orbit coupling (SOC) and realized in magnetic…
Janus transition metal dichalcogenides are an emerging class of atomically thin materials with engineered broken mirror symmetry that gives rise to long-lived dipolar excitons, Rashba splitting, and topologically protected solitons. They…
Group-IV monochalcogenides are a family of two-dimensional puckered materials with an orthorhombic structure that is comprised of polar layers. In this article, we use first principles calculations to show the multistability of monolayer…
By a combined study with first-principles calculations and symmetry analysis, we theoretically investigate the electronic properties of monolayer MoSi$_2$N$_4$. While the spin-orbital coupling results in bands splitting, the horizontal…
The Janus structure, by combining properties of different transition metal dichalcogenide (TMD) monolayers in a single polar material, has attracted increasing research interest because of their particular structure and potential…
We predict enormous piezoelectric effects in intrinsic monolayer group IV monochalcogenides (MX, M=Sn or Ge, X=Se or S), including SnSe, SnS, GeSe and GeS. Using first-principle simulations based on the modern theory of polarization, we…
In a recent work, new two-dimensional materials, the monolayer MoSi$_{2}$N$_{4}$ and WSi$_{2}$N$_{4}$, have been successfully synthesized in experiment, and several other monolayer materials with the similar structure, such as…
Manipulation of spin-polarized electronic states of two-dimensional (2D) materials under ambient conditions is necessary for developing new quantum devices with small physical dimensions. Here, we explore spin-dependent electronic…
Reduced dielectric screening in two-dimensional materials enables bound excitons, which modifies their optical absorption and optoelectronic response even at room temperature. Here, we demonstrate the existence of excitons in the bandgap of…
The realization of multifunctional two-dimensional (2D) materials is fundamentally intriguing, such as combination of piezoelectricity with topological insulating phase or ferromagnetism. In this work, a Janus monolayer…