Defect-governed double-step activation and directed flame fronts

Abstract

Defects play a crucial role in physics of solids, affecting their mechanical, electromagnetic, and chemical properties. However, influence of thermal defects on wave propagation in exothermic reactions (flame fronts) still remains poorly understood at molecular level. Here, we show that thermal behavior of the defects exhibits essential features of double-step exothermic reactions with pre-equilibrium. We use experiments with monolayer complex (dusty) plasma and find that it can show a double-step activation thermal behavior, similar to chemically-reactive media. Furthermore, for the first time we demonstrate capabilities to control flame fronts using defects and the different dynamic regimes of the thermal defects in complex (dusty) plasmas, from non-activated one to being sound-and self-activated (like in active soft matter). The results suggest that a range of challenging phenomena at the forefront of modern science (e.g. defect activation, flame front dynamics, reaction waves etc.) can now be experimentally interrogated on a microscopic scale.

Direct Experimental Evidence of Longitudinal and Transverse Mode Hybridization and Anticrossing in Simple Model Fluids

“…In order to observe mode anticrossing directly, we performed dedicated experiments with 2D system of charged microparticles in the same manner as described previously. [32][33][34][35][36] To prepare the fluid, we melted 2D complex plasma crystal utilising the mode-coupling instability [36][37][38] (see details in SI 31 ), however, the same could be done using laser heating. 39,40 First, the model fluid system was set up.…”

“…(The latter is also described in detail in the Supporting Information (SI).) To observe mode anticrossing directly, we performed dedicated experiments with a 2D system of charged microparticles in the same manner as previously described. − To prepare the fluid, we melted a 2D complex plasma crystal utilizing the mode-coupling instability − (see details in the SI); however, the same could be done using laser heating. , …”