Stacking-Dependent Magnetism in Bilayer CrI₃

Abstract

We report the connection between the stacking order and magnetic properties of bilayer CrI3 using first-principles calculations. We show that the stacking order defines the magnetic ground state. By changing the interlayer stacking order one can tune the interlayer exchange interaction between antiferromagnetic and ferromagnetic. To measure the predicted stacking-dependent magnetism, we propose using linear magnetoelectric effect. Our results not only gives a possible explanation for the observed antiferromagnetism in bilayer CrI3 but also have direct implications in heterostructures made of two-dimensional magnets.

Recent Advances in Quantum Effects of 2D Materials

“…First, with the devotion of substantial research efforts, a number of new 2DLMs can be explored, with notable discoveries benefiting both fundamental and applied studies of quantum science. For example, the emergence of 2D magnetic insulators (e.g., CrI 3 ) extends the possibilities of novel device applications, such as spin‐filters and valley manipulation, through vdW heterostructure engineering . Besides, similar emerging 2DLM systems of VSe 2 , VAgP 2 S 6 , CuCrP 2 S 6 , and MnPSe 3 have also aroused much attention due to their outstanding performances in building ferrovalley devices and spin electronics …”

Van der Waals magnets: Wonder building blocks for two‐dimensional spintronics?

“…Besides the experimental effort in exploring the 2D magnetism, recent theoretical investigations have shown a strong dependence of the magnetic interlayer coupling in CrI 3 on stacking structure. In particular, a rhombohedral stacking structure is predicted to favor a ferromagnetic interlayer coupling, whereas a monoclinic stacking structure is coupled antiferromagnetically . For bulk CrI 3 crystal, a structural phase transition from a low‐temperature rhombohedral structure to a high‐temperature monoclinic structure is known to exist at ~200 K .…”

“…In particular, a rhombohedral stacking structure is predicted to favor a ferromagnetic interlayer coupling, whereas a monoclinic stacking structure is coupled antiferromagnetically. [70][71][72][73] For bulk CrI 3 crystal, a structural phase transition from a low-temperature rhombohedral structure to a high-temperature monoclinic structure is known to exist at~200 K. 57 Recently, the magnetic structure due to spin-lattice coupling in bilayer CrI 3 has been studied by second harmonic generation (SHG) at low temperatures. 74 The authors observed giant nonreciprocal SHG originating from layered antiferromagnetic order, which breaks both the spatial-inversion and time-reversal symmetries.…”

Ultrathin Scattering Spin Filter and Magnetic Tunnel Junction Implemented by Ferromagnetic 2D van der Waals Material

“…According to the Mermin–Wagner theorem,18 2D long‐range FM order cannot exist in an isotropic magnetic system. Recently, people found that 2D layered CrI 3 ,19–27 Cr 2 Ge 2 Te 6 ,28 and CrSiTe 3 29 possesses intrinsic magnetocrystalline anisotropy against thermal fluctuations. However, the Curie temperatures of CrI 3 , Cr 2 Ge 2 Te 6 , and CrSiTe 3 are only dozens of Kelvins.…”

“…According to the Mermin-Wagner theorem, [18] 2D long-range FM order cannot exist in an isotropic magnetic system. Recently, people found that 2D layered CrI 3 , [19][20][21][22][23][24][25][26][27] Cr 2 Ge 2 Te 6 , [28] and CrSiTe 3…”