Magnon-magnon interaction and magnon relaxation time in a ferromagnetic Cr2Ge2Te6 monolayer

Abstract

Despite the intense amount of attention and huge potential of two-dimensional (2D) magnets for applications in novel magnetic, magneto-optical, magneto-thermal and magneto-electronic devices, there has yet to be a robust strategy developed to systematically understand magnon-magnon (MMI) interactions at finite temperature. In this paper, we present a first-principles theoretical method to introduce the finite temperature magnon-magnon interaction into Heisenberg Hamiltonian through a nonlinear correction energy. The Wick's theorem is used to decouple the four-magnon operators to twomagnon order. We demonstrate the capabilities of this method by studying the strength of MMI in Cr2Ge2Te6 (CGT) monolayer. The spin wave spectrum at finite temperature and the time-dependent spin autocorrelation function are explored. It is found that the magnon relaxation time due to magnon-magnon scattering increases with temperature because of the reduction in magnon energy, while decreases with wavevector and external magnetic field. Our results provide a new insight to understand the magnon damping and energy dissipation in two-dimensional ferromagnetic materials.

Magnetic anisotropy and ferroelectric-driven magnetic phase transition in monolayer Cr2Ge2Te6

“…1(c)), which is consistent with the previous works. 41,59 Additionally, the thermal stability of ML-CGT lattice is assessed by performing ab initio molecular dynamics (MD) simulations. We use a 3 × 3 supercell to carry out the individual simulations at a temperature of 300 K within 20 ps.…”

Non-coding RNA Activated by DNA Damage: Review of Its Roles in the Carcinogenesis

“…Therefore, in addition its role in the initiation of cancer possibly through influencing genomic stability, NORAD partakes in the progression of cancer through enhancement of EMT. In addition, NORAD has a role in the modulation of response of cancer cells to a number of chemotherapeutic drugs such as doxorubicin and cisplatin (Huang et al, 2020;Wang et al, 2020).…”

“…In neuroblastoma, in addition to enhancement of cell proliferation and invasion, NORAD increases doxorubicin resistance possibly through suppression of apoptosis and autophagy. These effects are exerted through miR-144-3p/HDAC8 axis (Wang et al, 2020). In osteosarcoma cell lines, NORAD regulates cancer cell features via acting as a molecular sponge for hsa-miR-199a-3p (Wang et al, 2019).…”

“…Apart from this study, other in vivo studies have shown the role of NORAD in enhancement of tumor progression in animal models. For instance, NORAD increases the growth of neuroblastoma tumors in animal models via miR-144-3p/HDAC8 axis (Wang et al, 2020). Moreover, growth of osteosarcoma tumors in animals has been attenuated by NORAD silencing in the implanted cells (Wang et al, 2019).…”

Massless Dirac magnons in the two dimensional van der Waals honeycomb magnet CrCl3

“…Such behavior is in remarkable contrast to the excitation spectra of CrI 3 or CrBr 3 , which exhibit significant broadening in energy throughout their magnon bands at low temperatures [5,6,32]. The magnon broadening in insulating ferromagnets typically occurs via magnon-magnon interactions or magnon-phonon coupling as the temperature approaches T C [44,45,46]. We thus stress that the resolution-limited magnon in CrCl 3 at T = 4 K is considered normal whereas the magnon broadening observed in CrI 3 and CrBr 3 are anomalous.…”