Nano-electronics is an emergent interdisciplinary area covering a diverse range of advanced electronic materials and devices, with the common characteristic that they are so small that dimensional effects, inter-atomic interactions and quantum phenomena need to be studied extensively.  Our team performs cutting-edge research on a set of low dimensional quantum materials and devices with the aim of revealing new physics and translating experiments into life-changing technologies.

For more details, please visit our complete research profile on PURE.

Our research covers a diverse set of advanced electronic materials particularly in their nano-forms. For applied materials, the spin ordering has long been investigated within the context of conventional ferromagnetic metals and their alloys, while the study of spin generation, relaxation, and spin-orbital engineering in non-magnetic materials has taken off rather recently with the advent of spintronics (spin-electronics) and it is here that many novel material systems can find their greatest potential in both science and technology. In the pursuit for such goals, the intrinsic material properties are important indicators and the artificially synthetized hybrid systems are valuable models for studying spin-dependent phenomena and could potentially be used as actual components for an eventual logic device.

The experimental side of the research today has marched to a historical point where the paramount urgency is to use materials of the highest perfection and homogeneity and detection tools with atomic sensitivity. At the Nano Group, we perform world-class research using a set of state-of-the-art techniques to produce designer materials and ‘see’ deep inside the atoms using the synchrotron-radiation based high resolution x-rays. We routinely work at the national facility SuperFab Nanocentre and Harwell Campus, and collaborate with worldwide universities and research institutes.

Bryan et al. “Metachronal waves in magnetic micro-robotic paddles for artificial cilia”, Nature Communication Materials 2, 14 (2021)

Liu et al. “Light-Tunable Ferromagnetism in Atomically Thin Fe3GeTe2 Driven by Femtosecond Laser Pulse”, Physical Review Letters 125, 267205 (2020).

Liu et al. “Two-dimensional ferromagnetic superlattices”. National Science Review, 7, 745 (2020)

Liu et al. “Experimental observation of dual magnetic states in topological insulators”, Science Advances 5, eaav2088 (2019)

Liu et al. “Hybrid Spintronic Materials: Growth, Structure and Properties”, Progress of Material Science 99, 27 (2018).

Bryan et al. “Nanoscale switch for vortex polarization mediated by Bloch core formation in magnetic hybrid systems”, Nature Communications 6, 7836 (2015)

Liu et al. “Atomic-Scale Magnetism of Cr-Doped Bi₂Se₃Thin Film Topological Insulators”, ACS Nano 9, 99 (2015).

Liu et al. “Enhancing Magnetic Ordering in Cr-Doped Bi2Se3 Using High-TC Ferrimagnetic Insulator”, Nano Letters 15, 764 (2015).

Liu et al. “Ferromagnetic Interfacial Interaction and the Proximity Effect in a Co₂FeAl/(Ga,Mn)As Bilayer”, Physical Review Letters 111, 027203 (2013).

Topological materials. Topological materials feature novel phases of quantum matter with sharp transitions in the electronic structure near their surfaces. Unlike the divergent electronic properties of surface and bulk regions of all solids, owing to the inevitable termination of the periodic lattice structure when approaching the boundaries, topological materials present a new class of nontrivial surface states arising from intrinsic strong spin-orbit coupling and characterized by Rashba spin texture.

Topological Spintronics. This EPSRC funded project (EP/S010246/1) focuses on the experimental studies (nano-fabrication and characterisation) of magnetic topological insulators that are expected to give rise to Quantum Anomalous Hall effect and further coherent spin transport phenomena.

2D materials. Van der Waals materials and their heterostructures 2D systems are one of the most exciting classes of materials due to the wealth of exceptional physical properties that occur when charge, spin and heat transport are confined to a plane. Their unique 2DEG-like behaviour not only enriches the world of low-dimensional physics, but also provides a platform for transformative technical innovations.

3D magnetism. Reducing the size of magnetic materials down to the nanoscale enables the magnetization configuration to be controlled.  We are examining how this control can be extended through nanoscale design of a structure in three dimensions.   Layering materials causes imprinting of characteristics of one layer into another.  This enables magnetic properties to be tailored, creating devices with new functionality.

Magnetic Micro-robots. Magnetic micro-robots that can be actuated within fluids have grown into a thriving field of research due to their potential medical applications in drug delivery and microsurgery. Due to the microscale dimensions of these robots, viscosity dominates over inertial motion, a regime characterized by a low Reynolds number. Control over the actuation sequence of the robots enables the limitations imposed by operating in a low Reynolds number environment to be overcome.

Garnets and complex oxides. Ferrimagnetic garnet is an excellent insulator with low Gilbert damping and a Curie temperature well above room temperature, that has been incorporated into heterostructures that exhibit a plethora of spintronic phenomena including spin pumping, spin Seebeck, and proximity effects.

To apply for an MSc by Research or PhD within the Nano Group, applicants should hold, or be predicted to achieve, a First-Class degree or equivalent in one of the following subjects: Physics, Material Science, and Engineering. Some laboratory research experience in physical subjects and relevant track records would be advantageous. Applicants are encouraged to send their CV to the Group Head, Dr Wenqing Liu, on wenqing.liu@rhul.ac.uk for an informal discussion before the online application. Academic visiting opportunities are open all year round.

PhD research topics open for applications

Advanced topological matters: The recently discovered topological phase (Nobel Prize in Physics 2016) has presented new possibilities for Quantum Materials: even the insulating state of matter exhibits a conductivity at the edges of certain physical systems and such conductive states are nontrivial and robust. Their unique behaviours not only enrich the world of low-dimensional physics, but also provide a platform for transformative technical innovations like quantum computation and communication. This project will perfrom experimental studies of (magnetic) topological matters that are expected to give rise to Quantum Anomalous Hall effect and further coherent spin transport phenomena. Project supervisor Dr Wenqing Liu. Project reference: WL1

Magnon spintronics: Magnons are the quanta of spin waves: the dynamic eigen-excitations of a magnetically ordered body. Analogous to electric currents, magnon-based currents can be used to carry, transport and process information. This allows the implementation of novel wave-based computing technologies free from the drawbacks inherent to modern electronics such as Joule heat. Logic circuits based on wave interference and nonlinear wave interaction can be designed with much smaller footprints compared with conventional electron-based logic circuits. (Nature Physics volume 11, pages 453) This project will explore the material and device architectures for Magnon spintronics. Project supervisor Dr Wenqing Liu. Project reference: WL2

Magnetic vortices in 3D systems. Nanoscale technology enables magnetic behaviour to be controlled using the shape of patterned elements.  Magnetic vortices are topological features present in circular elements, in which the magnetization rotates continuously within the structure plane, except for a central core that has perpendicular magnetization.  Oscillating vortices have the potential to be used as low power amplifiers, but this function is inhibited if the vortex core magnetization reverses during oscillation.  Using micromagnetic modelling, this PhD will explore how producing a 3D magnetic profile may improve vortex core stability and open up new applications for magnetic vortices. Project supervisor Dr Matthew Bryan. Project reference: MT1

Magnetization dynamics in 3D. Movement of domain walls – boundaries between regions of opposing magnetization – is a fundamental mechanism through which magnetization reverses direction.  Understanding domain wall behaviour is therefore essential for efficiently switching magnetic states with a device.  In planar nanostructures, domain walls have been proposed for several data processing, data storage and sensor applications.  3D fabrication promises opportunities to further expand the capabilities of magnetic devices, but it is unclear how the additional complexity of a 3D system changes magnetic reversal mechanisms.  This PhD will examine the role 3D geometries play in determining domain wall structure and motion. Project supervisor Dr Matthew Bryan. Project reference: MT2

We collaborate with worldwide universities, research institutes, national laboratories and industrial partners. We acknowledge the support from EPSRC, STFC, RAEng, Royal Society and Leverhulme trust.