ABSTRACT
The temporal characters of laser-driven phase transition from 2H to 1T^{'} has been investigated in the prototype MoTe_{2} monolayer. This process is found to be induced by fundamental electron-phonon interactions, with an unexpected phonon excitation and coupling pathway closely related to the nonequilibrium relaxation of photoexcited electrons. The order-to-order phase transformation is dissected into three substages, involving energy and momentum scattering processes from optical (A_{1}^{'} and E^{'}) to acoustic phonon modes [LA(M)] in subpicosecond timescale. An intermediate metallic state along the nonadiabatic transition pathway is also identified. These results have profound implications on nonequilibrium phase engineering strategies.
ABSTRACT
Two-dimensional topological materials have attracted intense research efforts owing to their promise in applications for low-energy, high-efficiency quantum computations. Group-VA elemental thin films with strong spin-orbit coupling have been predicted to host topologically nontrivial states as excellent two-dimensional topological materials. Herein, we experimentally demonstrated for the first time that the epitaxially grown high-quality antimonene monolayer islands with buckled configurations exhibit significantly robust one-dimensional topological edge states above the Fermi level. We further demonstrated that these topologically nontrivial edge states arise from a single p-orbital manifold as a general consequence of atomic spin-orbit coupling. Thus, our findings establish monolayer antimonene as a new class of topological monolayer materials hosting the topological edge states for future low-power electronic nanodevices and quantum computations.
ABSTRACT
OBJECTIVE: To explore the changes in the threshold of auditory brainstem response (ABR) and [Ca(2+)]I and calmodulin (CaM) in cochlear nucleus of newborn mice infected by murine cytomegalovirus (MCMV) in the brain. METHODS: Sixty-nine newborn mice were randomized into model group and control group. The model group (54 mice) was established by intracranial injection with MCMV viral suspension 20 l and the same volume of 0.9% sodium chloride was injected in the control group (15 mice). After 1 month, the ABR was tested in a sound-electric screen environment and the threshold was recorded. Then intracellular free calcium [Ca(2+)]i and the mRNA level of CaM in the cochlear nucleus were assayed by flow cytometry and RT-PCR. RESULTS: Compare to the control group [(64.0 ± 1.3) dBSPL], the threshold of ABR in the model group [(84.5 ± 2.7) dBSPL] was increased (F = 2.789,P = 0.000). Moreover, in the model group the intracellular free calcium [Ca(2+)]i and the mRNA level of CaM in the cochlear nucleus were increased (F = 1.290, P = 0.000; F = 4.252, P = 0.023), and the differences were statistically significant. CONCLUSIONS: The intracranial injection of MCMV can lead to abnormal changes in the threshold of ABR in mice, and the change of [Ca(2+) ]I/CaM in cochlear nucleus may be the important pathological basis of sensorineural hearing loss induced by MCMV infection.
