Short- and long-term prediction of solar activity and space weather are long-standing problems, affecting the society at a large scale: being able to issue a prediction earlier and more reliably will prevent economic losses for industries, space sector, and governments. During our ongoing ERC CoG project UniSDyn, we have numerically and observationally demonstrated the potential of a novel data product, the internal surface gravity oscillation mode, tracing the sub-surface magnetic field in the Sun, and here formulated methodologies to build prediction tools based on it both over short and long timescales. Earlier prediction methods have relied on magnetic fields on the solar surface or in the interplanetary space, while now we propose to use the solar internal oscillations as basis of the predictions - hence our ideas are novel and ground-braking. Innovation potential is augmented by the demonstrated capacity of the team to perform the demanding data analysis of the required data products for the proof-of-concept tools. Large innovation potential is also contained in new type of data service to be built: they augment the sustainability and re-usability of generic scientific data products, and enhance the renewal of science.

Active particles refer to out-of-equilibrium self-propulsive objects such as biological microswimmers and engineered colloidal particles that can form various fascinating collective states. Active particles are easy to observe experimentally but notoriously difficult to interact with due to their fast and stochastic dynamics at both single-particle and collective state levels. In this project, I aim at scientific breakthrough in both instrumentation that allows direct interaction with active particles and using the methodology to progress substantially our understanding of dynamics and phase transitions of active particles. The first part focuses on rendering active particles, including E. coli, C. reinhardtii and Quincke rollers, permanently magnetized and designing suitable hardware for controlling them in real time. These particles are rendered “intelligent” by programming their behavior based on real-time image analysis (long-range vision) and steering with external magnetic field. I will program these particles to reveal the limits of using local dissipative hydrodynamic near-fields to guiding active particles, and demonstrate unambiguously the extent to which a single active particle within a collective state can control the collective behaviour. The second part aims at realizing tuneable magnetic traps and other conservative potential energy landscapes for non-magnetic active particles by using magnetophoresis in superparamagnetic fluids. I will use the technique to establishing confinement-activity phase diagrams for both biological (C. reinhardtii) and synthetic (Quincke rollers) active particles in quadratic confinements. I will further reveal the role of dimensionality (1D vs 2D vs 3D) in the phase transitions of active particles and carry out the seminal investigation of active particles in periodic potentials. The results and methodologies will have a major impact, both immediately and in long-term, on experimental physics of active particles.

Joule heating due to electrical resistance associated with current spreading in semiconductors is a significant loss mechanism in modern state-of-the-art high power light emitting diodes (LEDs) and high concentration solar cells. These losses can account for up to 10-30 % of the device power consumption under high power conditions, and thereby dramatically reduce the efficiency of solar energy harvesting and general lighting, whose efficiencies – apart from the resistive losses – are gradually closing in on their theoretical limits. In ZeroR we make use of a conceptually simple but functionally dramatic modification to the previous buried active region (AR) devices, like LEDs, lasers and solar cells, by relocating the AR to outside the pn-junction, allowing e.g. locating the AR on the device surface – or locating all the contact structures fully on one side of the active region, eventually enabling a fully scalable and essentially resistance free structures. We analyze the commercial prospects of the technology and show that it provides new freedom for high power semiconductor device design. The main goal of ZeroR is to facilitate further commercial development of the concept and to demonstrate the elimination of resistive losses in industrially relevant LED and solar cell prototypes using gallium nitride and gallium arsenide based compound semiconductor material systems. If successful, this approach can substantially increase the device efficiency at selected high power operating conditions and substantially expedite the ongoing solid state lighting revolution and market penetration, also providing more efficient new solutions for solar energy harvesting and selected other applications.

In researches about hydrogen oxidation reaction (HOR) at the anode of a fuel cell, most researchers concentrate on the intrinsic activity and stability of catalysts, while few researches study the gas diffusion effect in depth, which is however the rate-determine step for most HOR. Enlightened by the efficient lungs’ supply of oxygen to human with multistage bronchi and pulmonary alveoli, we plan to improve the hydrogen gas diffusion for HOR by constructing multistage superaerophilic gas channels (MSGC) in the catalyst layer (CL). Traditionally, to build gas channels in CL, people modify powder catalysts with aerophilic binder, which however cause aggregation and therefore hindered the transfer of electron and mass. Besides, part of the randomly made gas channels are closed that cannot transfer hydrogen actually. Thus, there are two challenges in MSGC construction: a solid and strong hierarchical micro-nano skeleton, that won’t aggregate, to support catalyst and channels, and a method to control the direction of the channels. Herein, we propose tungsten carbide nanoarrays (WC NA) as the skeleton for Pt catalyst and invent a vacuum-control method based on superwetting technology to direct the gas channels. Although WC nanoparticles have been proved promising as the substrate of Pt for HOR, WC NA has never been tried. Based on the novel structure, we will study the relationship between structure, gas diffusion, and HOR efficiency in depth. Targeting at the rate-determine step of HOR, we’re expecting a theoretical breakthrough in HOR, which will offer an alternative approach for making hydrogen anode in fuel cell industry.

Sandwiching ultra-thin out-of-plane magnetized materials between heavy metal and oxide layers in multilayer heterostructures has led to important new discoveries which offer a path to fast, non-volatile, low power electronics. The first important effect, the Dzyaloshinskii-Moriya interaction (DMI), favours orthogonal alignment of neighbouring spins, causing stable Néel domain walls of well-defined chirality. The second, spin-orbit torques (SOTs), are torques on the magnetization caused by spin accumulation under applied in-plane currents. In combination these effects lead to very high domain wall velocities and allow the creation of mobile topological objects called skyrmions, both suitable for technological applications. While DMI and SOTs are dominated by the interfaces, their precise microscopic origins are not well understood. This proposal takes advantage of newly developed techniques to control magnetic interfaces with electric fields. Through strain effects, created by electric fields on a ferroelectric layer, or through electrical fields across an insulating oxide or through electric field-induced oxygen migration in an ionic conductor, the interfacial properties of suitable devices will be altered. All these effects change the filling of hybridized interfacial electronic orbitals, which allows the strength of the DMI and SOTs to be tuned for applications and lead to a better understanding of the underlying mechanisms. Magintlec will be conducted at Aalto University where the host group provides frontier expertise and state-of-the-art experimental facilities for electric-field controlled magnetism (film growth, lithography, magnetic and magnetotransport characterization). The applicant, Dr Rhodri Mansell, brings an excellent track record in nanomagnetism and spintronics. For the last five years, he worked as a postdoctoral research associate at Cambridge University focusing on spin-orbit effects and logic devices in out-of-plane magnetized multilayers.