First-principles study on multiferroicity in the Cr₂Ge₂Te₆/In₂Se₃ heterostructure influenced by finite strains

Multiferroic materials that have more than two ferroicities at the same time have long been regarded as one of the strongest candidates to achieve technological breakthroughs in many kinds of nanodevice applications. Various types of multiferroic materials have been discovered and devised to date; however, related studies have been conducted without identifying a complete winner because each has a decisive disadvantage. The recently discovered multiferroicity in the 2D Cr₂Ge₂Te₆/In₂Se₃ van der Waals heterostructure represents an important opportunity to create a new turning point in multiferroic research. Through first-principles density functional theory calculations, we studied the preferential characteristics of the spin magnetic moment of 2D Cr₂Ge₂Te₆ induced by the ferroelectric switching of the In₂Se₃ monolayer in the presence of the strains that inevitably exist in any kind of heterostructure. From the results, we found that the multiferroicity in the Cr₂Ge₂Te₆/In₂Se₃ heterostructure reacts quite sensitively to the strain level, revealing the possibility of manipulating multiferroic properties in the structure.