Morphologies and dynamics of the interfaces between active and passive phases

Abstract

Active matters exhibit interesting collective behaviors and novel phases, which provide an important platform for the study of nonequilibrium physics. Mixtures of active and passive particles have been intensively studied...

Morphologies and dynamics of free surfaces of crystals composed of active particles

“…γ increases with Pe. Such superdiffusive behaviour has also been observed for the active–passive interface 48 and is distinct from the normal diffusion ( γ = 1) at passive liquid–gas interfaces 64 and grain boundaries. 65 At long times, γ < 1 ( i.e.…”

“…g increases with Pe. Such superdiffusive behaviour has also been observed for the active-passive interface 48 and is distinct from the normal diffusion (g = 1) at passive liquid-gas interfaces 64 and grain boundaries. 65 At long times, g o 1 (i.e., corresponding to subdiffusive behaviour) because the surface cannot diffuse away from its steady position as the other end of the crystal is fixed at the wall.…”

“…46,47 The surface roughness ω ( l , t ) usually exhibits the dynamic scaling relation ω ( l , t ) = t β f ( u ≡ l / ξ ( t )) in space and time with the following scaling function: 67 Thus,Here, the lateral correlation length ξ ( t ) ∼ t 1/ z , where z is the dynamic exponent, α is the roughness exponent, β is the growth exponent, and the time exponent κ ≡ β − α / z = 0 and >0 correspond to normal and anomalous roughening, respectively. 15,18,48,67 ω ( l , t ) exhibits Family–Vicsek dynamic scaling, 18 i.e. , normal roughening, in discrete growth modes for particle deposition 15,18 and growth fronts described by EW 20 or KPZ 21 continuum dynamic growth equations.…”

“…Here, the lateral correlation length x(t) B t 1/z , where z is the dynamic exponent, a is the roughness exponent, b is the growth exponent, and the time exponent k b À a/z = 0 and 40 correspond to normal and anomalous roughening, respectively. 15,18,48,67 o(l,t) exhibits Family-Vicsek dynamic scaling, 18 i.e., normal roughening, in discrete growth modes for particle deposition 15,18 and growth fronts described by EW 20 or KPZ 21 continuum dynamic growth equations. Anomalous roughening with k 4 0 usually occurs at vapour-solid interfaces with steep local slopes due to fast particle deposition 68 and been observed in some nonequilibrium kinetic roughening systems, such as tumour growth fronts, 57 MBE growth, 19 and propagating wood fractured surfaces.…”

“…46,47 In ref. 48, we studied the morphology and dynamics of interfaces between active and passive phases. Here, we use similar analysis methods to study the crystal-gas interfaces in purely active systems during and after crystal growth.…”