Harmonic vibrational excitations in graded elastic networks: transition from phonons to gradons
J. J. Xiao, K. Yakubo, K. W. Yu
Abstract
We have identified a new type of transition from extended to localized vibrational states in one-dimensional graded elastic chains of coupled harmonic oscillators, in which the vibrating masses or nearest-coupling force constants vary linearly along the chain. We found that the delocalization transition occurs at the maximum frequency of the corresponding homogeneous chain, which is in a continuous single band. Although each state in the localized phase, called gradon, can be regarded as an impurity localized mode, the localization profile is clearly distinct from usual impurity modes or the Anderson localized modes. We also argue how gradons may affect the macroscopic properties of graded systems. Our results can provide insights into many analogous systems with graded characters.
Create a lesson
Related papers
Temperature dependence of the charge density from first principles: application to the (222) forbidden reflection in silicon
Jean Paul Nery, Raveena Gupta, Olle Hellman et al.
Coupled anisotropic weak topological states and Floquet mixed-parity altermagnetism in two-dimensional Su-Schrieffer-Heeger models
Kunyuan Feng, Xibin Liu, Chenchen Liu et al.
Grain Boundary Phase Transitions Enable Diffusionless Climb of Disconnections
Md Sharier Nazim, Giacomo Po, Nikhil Chandra Admal
3D Cloud Component Analysis of Atomic Structures
Pai Li
Benchmarking of Fast and Interpretable UF Machine Learning Potentials
Pawan Prakash, Sam Dong, Richard G. Hennig
Grain-Boundary Premelting in High-Entropy Transition Metal Carbides
Marium M. Mou, Caleb Schenck, Samuel E. Daigle et al.