Related papers: Negative piezoelectricity in low--dimensional mate…
The competition between the electron-hole Coulomb attraction and the three-dimensional dielectric screening dictates the optical properties of layered semiconductors. In low-dimensional materials, the equilibrium dielectric environment can…
Despite extensive research on piezoelectric polymers since the discovery of piezoelectric poly(vinylidene fluoride) (PVDF) in 1969, the fundamental physics of polymer piezoelectricity has remained elusive. Based on the classic principle of…
Consistently atomistic understanding of the mechanism behind the intriguing behavior of low-dimensional systems including monatomic chains, hollow tubes, surface skins, nanocavities, nanowires, and nanograins has long been a high challenge.…
The macroscopic dielectric permittivity of dielectric crystals is related to the microscopic atomic polarizability of constituent atoms by the known Clausius-Mossotti relation obtained in the middle of 19th century. We derive a similar…
Compound phases often display properties that are symmetry-forbidden relative to their nominal, average crystallographic symmetry, even if extrinsic reasons (defects, strain, imperfections) are not apparent. Here, we investigate macroscopic…
The piezoelectric response is a measure of the sensitivity of a material's polarization to stress or its strain to an applied field. Using in-operando x-ray Bragg coherent diffraction imaging, we observe that topological vortices are the…
The origin of "giant" flexoelectricity, orders of magnitude larger than theoretically predicted, yet frequently observed, is under intense scrutiny. There is mounting evidence correlating giant flexoelectric-like effects with parasitic…
Altermagnetism, featuring alternating spin structures in reciprocal space, has sparked growing interest. Here, we predict novel real-space alternative piezomagnetic and piezoelectric responses in an emerging altermagnetic family of Lieb…
An unresolved issue in the commonly used Pb(Zr1-xTix)O3 (PZT) ceramics is understanding the intrinsic piezoelectric behaviors of its crystal around the morphotropic phase boundary (MPB). Here, we demonstrate a novel approach to grow c-axis…
We study the effect of the off-diagonal elements of the Wannier Hamiltonian on the electronic structure of low-symmetry material Li$_2$MnO$_3$ ($C2/m$), using dynamical mean field theory calculations with continuous-time Quantum Monte Carlo…
Understanding the effect of electric fields on the physical and chemical properties of two-dimensional (2D) nanostructures is instrumental in the design of novel electronic and optoelectronic devices. Several of those properties are…
As a canonical response to the applied magnetic field, the electronic states of a metal are fundamentally reorganized into Landau levels. In Dirac metals, Landau levels can be expected without magnetic fields, provided that an inhomogeneous…
Flexoelectricity is a universal effect that generates electric polarization due to broken inversion symmetry caused by local strain gradient. The large strain gradient at nanoscale makes flexo-electric effects, especially in nanoscopic…
We have investigated the electronic, vibrational, optical, thermal and piezoelectric properties of LiNbO$_3$, LiTaO$_3$ and Li$_2$NbTaO$_6$ using the first-principles calculation based on the density functional theory. It also shows…
When the electron density of highly crystalline thin films is tuned by chemical doping or ionic liq- uid gating, interesting effects appear including unconventional superconductivity, sizeable spin-orbit coupling, competition with…
Understanding various aspects of ferroelectricity in hafnia-based nanomaterials is of vital importance for the development of future non-volatile memory and logic devices. Here, the unconventional and weak electromechanical response of…
The combination of metallicity and ferroelectricity breaks traditional boundaries, paving new avenues for innovative electronic materials and devices. This breakthrough is particularly notable, as metallicity and ferroelectricity have…
Low-dimensional multiferroicity, though highly scarce in nature, has attracted great attention due to both fundamental and technological interests. Using first-principles density functional theory, we show that ferromagnetism and…
Surprising asymmetry in the local electromechanical response across a single antiparallel ferroelectric domain wall is reported. Piezoelectric force microscopy is used to investigate both the in-plane and out-of- plane electromechanical…
We developed a Landau type theory for the description of polar phenomena in low-dimensional transition metal dichalcogenides (TMDs), specifically exploring flexoelectric origin of the polarization induced by a spontaneous bending and by…