Department of complex matter

Dynamics of complex nanomaterials

Publications

2017

Patents and innovations

2017

The aim of the research programme is to investigate the nonequilibrium dynamics of nonlinear complex systems in condensed matter using a carefully chosen combination of experimental and theoretical methods.

The main original idea behind this research pioneered by our group is that non-ergodically freely-evolving systems reveal new physics compared with traditional experiments performed under ergodic conditions in which only one external parameter is controlled, such as temperature, pressure, external field etc.. In temporally evolving systems, the dynamics through symmetry-breaking transitions is mainly governed by one particular excitation, without interference from other excitations of the underlying vacuum (electrons, phonons, magnons). We will address fundamental questions on the effect of symmetry and fundamental interactions of underlying microscopic vacua on global emergent behaviour. This will give us new insight into the mechanisms leading to symmetry breaking, and open up new possibilities in the study of the behaviour of matter under nonequilibrium conditions. It also promises a new generation of electronic devices based on complex materials, particularly nonvolatile memories.

The main experimental focus is on novel ultrafast spectroscopy techniques, some of which have been developed by our group (three pulse “cosmic quench” experiments). These will be complemented by nanoelectronics experiments, particularly charge transport by a new and revolutionary multi-probe STM technique in combination with optical excitation.

The research team is rejuvenated with some new members, with fresh relevant experience to kick-start the new experimental techniques in the proposed programme.
Emphasis will be placed on new materials exhibiting emergent properties as a result of collective excitations, whose phase transitions between different ordered states can be investigated in real time. The systems of interest here are a) the charge-ordered systems: layered transition metal tri-tellurides with dichalcogenides and the quasi 1D chain systems, b) oxide and pnictide superconductors, c) systems with competing order: pnictides and rare-earth vanadates.

The expertise of the group will also be applied to research with more immediate practical application potential: electron relaxation dynamics in solar cell materials leading to improved solar cell efficiency and nanoscale transport studies in new nanostructures without photoexcitation.

A very important part of the group activity is synthesis of new materials displaying different functional properties relevant in the present context using different methods, including molecular beam epitaxy, which enables us to have state of the art new materials for study, and at the same time allows us to rapidly develop possible applications.
The experimental efforts will be supplemented by theoretical modeling of nonlinear system dynamics and ordering which is crucial in bringing the experimental work to a much higher level.