Past Seminars Seminários Já Decorridos 2020

Emergent (and disappearing) Symmetries in Soft Matter Systems

By: Douglas Cleaver
From: Sheffield Hallam University, UK
At: zoom (https://videoconf-colibri.zoom.us/j/89992047308)
[2020-11-19] 10:00

Much of the utility of soft matter systems is founded in their ability to manifest symmetries and structural components over a broad swathe of time and length scales - and to undergo morphological change either spontaneously or in response to some stimulus. This can result in anisotropies (in optical or transport or mechanical or rheological properties) which are then available for nature or humankind to exploit. Sometimes, the link between molecular and phase symmetries is relatively straightforward. However, there are also many many situations where molecular symmetries are lost within many-body systems. Most obviously, liquid crystalline molecules are usually polar - but the phases they form are not. In this talk, we will use computer simulations of simple model representations of liquid crystalline and self-assembling systems to explore some of these emergent and disappearing symmetries. We will also examine how they can also lead to frustration effects and, thus, the appearance of length-scales which are orders of magnitude larger than any of the raw components. From this, we will gain insights into how assemblies start and, in some cases, stop growing, as well as some of the pathways inherent in achieving complex outcomes from apparently straightforward foundations.​