Ferroelectricity is a cornerstone of functional materials research, enabling diverse technologies from nonvolatile memory to optoelectronics. Recently, type-I integer quantum ferroelectricity (IQFE), unconstrained by symmetry, has been proposed and experimentally demonstrated; however, as it arises from ionic displacements of an integer lattice vector, the initial and final states are macroscopically indistinguishable, rendering the physical properties unchanged. Here, we propose the nontrivial counterpart (i.e., type-II IQFE) where the polarization difference between the initial and final states is quantized but the macroscopical properties differ. We further demonstrate the existence of type-II IQFE in bulk chiral tellurium. In few-layer tellurium, the total polarization remains nearly quantized, composed of a bulk-inherited quantum component and a small surface-induced contribution. Molecular dynamics simulations reveal surface-initiated, layer-by-layer switching driven by reduced energy barriers, explaining why ferroelectricity has been observed experimentally in few-layer tellurium but not in bulk tellurium. Interestingly, the chirality of the initial and final states in bulk tellurium is opposite, suggesting another way to control structural chirality with electric field in chiral photonics and nonvolatile ferroelectric memory devices.

Close

PrevNext

View figure in article

• Electric polarization
• Ferroelectricity
• Ferroelectrics
• Chiral symmetry
• Density functional theory
• Machine learning
• Wannier function methods