Welcome to our 23 new PGRs!

The EPSRC CDT in Metamaterials in September 2018. 62 PGRs and supervisors of our ~100 people strong Centre made it to this year’s networking event in Northcott Theatre and the subsequent group picture. Hoorah!

The CDT in Metamaterials sends a warm welcome to our 23 new PGRs. It was a real pleasure to see so many new faces and fresh energy arriving at the start of our induction week on 17 September 2018. We hope they will soon feel at home at Exeter and in their roles as postgraduate researchers – lots of challenges lie ahead, and we look forward to supporting their research and professional development over the next 4 years. I’m sure it’ll be an adventurous time with lots of new ideas for both scientific and community-building activities.

The best of luck to all XM² PGRs and supervisors for their endeavours in 2018/19.

2018 XM² cohort Theme Project  Supervisor 1 Supervisor 2 Supervisor 3
Benjamin Pearce Acoustic and Fluid-dynamical Metamaterials Metasurfaces and Phononic Crystals for Manipulating Fluid Flow and Acoustics Alastair Hibbins Roy Sambles Peter Petrov
Bethany Staples Acoustic and Fluid-dynamical Metamaterials Control of flow-induced near-field noise through the use of metasurfaces Alastair Hibbins Roy Sambles
Connor Sait quantum metamaterials A quantum thermodynamic study to improve magnetic data storage Janet Anders Simon Horsley Rob Hicken
Conor Price Nanomaterials and nanocomposites Two-dimensional Metamaterial Batteries Steve Hepplestone Misha Portnoi Saverio Russo
David Newman Magnonics, Spintronics and Magnetic Metamaterials Detection of magnetic meta-atom dynamics by x-ray ferromagnetism resonance Rob Hicken Mustafa Aziz
Dean Patient Optical, Infra-red and THz Photonics and Plasmonics Solid State Refrigeration using 2D/Meta materials) Geoff Nash Simon Horsley
Euan Humphreys Nanomaterials and nanocomposites The development of novel electronic and photonic metadevices for adaptive multispectral imaging in the infrared Wright Bertolotti
Hannah Barnard Optical, Infra-red and THz Photonics and Plasmonics Nanoscale Infrared Biomolecule Spectroscopy (NIBS) Geoff Nash JJ Phillips Isaac Luxmoore
Ineta Grikalaite Graphene and other 2D Materials, and related Devices Terahertz photonic metadevices with carbon nanomaterials Ana Neves Anna Baldycheva
Jacob Binsley Acoustic and Fluid-dynamical Metamaterials Magnetoelastic metamaterials for lab-on-a-chip technology Feodor Ogrin S Pagliara F Palombo
Jamie Le Signe Graphene and other 2D Materials, and related Devices Probing mechanics in quantum mechanics – Josephson nano-resonator metamaterials Saverio Russo Eros Mariani
Joe Shields Optical, Infra-red and THz Photonics and Plasmonics All dielectric phase-change metamaterial-based holography David Wright Jacopo Bertolotti Arseney Alexeev
Karl Jonas Riisnaes Graphene and other 2D Materials, and related Devices Strong light-matter interactions in perovskites Monica Craciun Saverio Russo Namphung Peimyoo
Katie Lewis Microwave metamaterials’ Advanced Magnetic Materials for Radio, Microwave and Millimetre-wave applications Alastair Hibbins Feodor Ogrin Roy Sambles
Kavya Sadanandan Graphene and other 2D Materials, and related Devices Plasmonic-enhanced organic photovoltaics for wearable applications Ana Neves Monica Craciun
Konstantinos Chatzimpaloglou Magnonics, Spintronics and Magnetic Metamaterials Optical detection of magnetization dynamics induced by spin orbit torques Rob Hicken Paul Keatley
Lucy Annett Magnonics, Spintronics and Magnetic Metamaterials Optically induced magnetization dynamics of magnetic exchange spring metamaterials Rob Hicken Janet Anders M K Dabrowski
Narima Eerqing Biological and Bio-inspired Metamaterials Testing fluctuation relations of conformal changes of biomolecules Frank Vollmer Janet Anders
Oliver Latcham Microwave Metamaterials Excitation of spin waves in magnetic elements using surface acoustic waves Volodymyr Kruglyak Geoff Nash Tom Hayward, University of Sheffield
Rachel Lennon Wave Theory and Spatial Transformations Towards flexible micro-endoscopy: compressive characterisation and control of light propagation through multi-mode optical fibres Dave Philips Jacopo Bertolotti
Sara-Kate Lavers Optical, Infra-red and THz Photonics and Plasmonics Microscopy in scattering media Jacopo Bertolotti Christian Soeller
Valentin Haemmerli Quantum Metamaterials Ultrafast single photon sources Isaac Luxmoore Bill Barnes
Wai Jue Tan Biological and Bio-inspired Metamaterials Photosynthetic Metamaterials Bill Barnes Isaac Luxmoore Philip Thomas

Impressions from our CDT induction networking event with PGRs from each cohort and their academic supervisors:

Our new PGRs in September 2018 – exciting times lie ahead! 🙂

E-MRS 2018 – XM2 members present their work at the European Materials Research Society conference in Warsaw

The XM² PGRs Ned Taylor, Francis Davies and Shane Davies are presenting their work at at the Fall European Material Research conference (E-MRS) in Warsaw, Poland with over 4000 attendees.

Founded in 1983, the European Materials Research Society now has more than 4,000 members from industry, government, academia and research laboratories, who meet regularly to debate recent technological developments of functional materials.

The XM² PGRs are giving talks on the following topics:

  • “Bandgap Engineering In Weakly Interacting Van der Waals Heterostructures”, (Francis)
  • “Tuning the properties of perovskite surfaces for photoelectrolysis” (Ned)
  • “Increasing thermoelectric ZT using interfacial patterning” (Shane)
Right to left: XM2 PGRs Francis, Ned, Shane and their supervisor Dr Steve Hepplestone
Ned Taylor: “Tuning the properties of perovskite surfaces for photoelectrolysis”
Shane Davies: “Increasing thermoelectric ZT using interfacial patterning”
Francis Davies: “Bandgap Engineering In Weakly Interacting Van der Waals Heterostructures”

 

SPIE in San Diego – XM2 PGRs present Exeter’s SPIE chapter activities

In September 2018, the XM² PGRs Erick Burgos Parra and Joaquin Faneca went to one of the most important events for optical engineering and applications, nanotechnology, quantum science, and organic photonics: SPIE OPTICS+ PHOTONICS (San Diego). They represented our EUOPS (Exeter University optics and photonics society) and the SPIE student chapter. Erick Burgos Parra was there as a facilitator of the event and Joaquin Faneca, president of the Exeter SPIE chapter, was awarded the SPIE officer travel grant to present a poster with the various activities the chapter has been developing.

Erick Burgos Parra and Joaquin Faneca presenting Exeter’s SPIE student chapter activities in San Diego (Sep 2018).

4 XM2 vivas successfully completed!

Graduation Cap and Diploma on White with Soft Shadow.

Very many congratulations to the EPSRC CDT in Metamaterials PGRs who completed their vivas (all with only minor corrections) in September 2018:

Well done all!

New Publication: Torque driven ferromagnetic swimmers

Congratulations to the EPSRC CDT in Metamaterials PGR Joshua Hamilton who has now published his latest work on Torque driven ferromagnetic swimmers in AIP Physics of Fluids together with Andrew D. Gilbert, Peter G. Petrov, and Feodor Y. Ogrin.

The publication is this month’s  “Editor’s Pick”, hence featured for about 5-6 weeks on the journal’s homepage: https://aip.scitation.org/journal/phf.

Well done all!

Measured flow speed along the channel as a function of frequency. The inset shows a schematic representation of the single ferromagnetic particle swimmer as a fluid pump. The base of the pin is attached to the base of the channel.

Microscopic swimming devices hold promise for radically new applications in lab-on-a-chip and microfluidic technology, including diagnostics and drug delivery. In this paper, we realize a macroscopic single particle ferromagnetic swimmer experimentally and investigate its swimming properties. The flagella-based swimmer is comprised of a hard ferromagnetic head attached to a flexible tail. We investigate the dynamic performance of the swimmer on the air-liquid interface as a function of the external magnetic field parameters (frequency and amplitude of an applied magnetic field). We show that the speed of the swimmer can be controlled by manipulating the strength and frequency of the external magnetic field (<3.5 mT) and that the propagation direction has a dependence on parameters of the external magnetic field. The experimental results are compared to a theoretical model based on three beads, one of which having a fixed magnetic moment and the other two non-magnetic, connected via elastic filaments. The model shows sufficient complexity to satisfy the “non-reciprocity” condition and gives good agreement with experiment. Via a simple conversion, we also demonstrate a fluid pump and investigate the induced flow. This investigation paves the way to the fabrication of such swimmers and fluid pump systems on a micro-scale, promising a variety of microfluidic applications.

Induction week 2018

23 new EPSRC CDT in Metamaterials PGRs will arrive for induction week on 17 September 2018. Induction week will see 1st year specific sessions, as well as networking events for the individual cohorts and time for interactions between all PGRs and supervisors.

Please see below the induction week schedule 2018. Please note, the Monday morning session will split as follows:

  • 09:00 – 09:30 am:  Welcome Breakfast with the new PGRs, their XM² PGR buddies, SAG and the Management Board.
  • 09:30 – 10:30 am:  Introduction to the CDT Metamaterials programme and information about what the new cohort can expect over the next 6 months and during their PhD & networking for 1st years, their supervisors and/or buddies.
  • 10:30 – 11:00 am: Closure of conversations and transfer of 1st years to Doctoral College induction.

If there are any questions please do not hesitate to get in touch with us via .

Training and other events in September to December 2018

The new academic year brings a busy schedule for the Metamaterials PGRs. Please find below a table of all upcoming XM² training and other events from September 2018 until early December 2018 as far as planning currently allows.

Yet to be confirmed:

  • The monthly CDT group meetings are likely to commence on 31 October 2018 – we are currently coordinating the time table to avoid clashes with research group meetings.
  • A few more training sessions (Magnetic Materials & Devices, Cognitive Behavioural Coaching) are yet to be confirmed by the facilitators.
  • There will be 3-4 x 1h CDT administrative induction sessions for 1st years shortly after induction week (administration requirements, XM² expectations – Dr A Roeding; training – Dr I J Luxmoore) and in November (progression & monitoring – Prof C D Wright).

PGRs, please highlight any XM²-training related absence times to your supervisors. In regards to annual leave or other absence time planning: All confirmed events have been sent to the PGRs via a calendar invitation, but please ensure to check the CDT in Metamaterials outlook calendar and to liaise with your supervisors and the CDT in Metamaterials office () for approval BEFORE you make any bookings, as there might be a few more events coming up that are yet to be confirmed.

Supervisors, please be mindful of the XM² events when setting expectations on research deliverables with the PGRs.

Date Training/Event Cohort Time Venue
September
10.09.18 M13 report Q&A session with David Wright 2nd years 14:30 – 15:30 G33
14.09.18 KTN ‘Metamaterials Applications Exploration’ Voluntary Workshop optional 13:30 – 16:00 Peter Chalk Building – Seminar Room 1.2
17.09.18 – 21.09.2018 Induction Week all PGRs and supervisors as required see induction week time table  see induction week time table
24.09.18 ‘How to be Creative’ workshop 1st years 9:00 – 12:30 Physics SCR
24.09.18 & 25.09.18 ‘Creativity Revisited’ Workshop optional for 2nd – 4th years 13:30 – 17:00 & 9:30 – 17:00 Physics SCR
27.09.18 Space Technology – Current Challenges and Visions for the Future optional 09:00 – 12:00 TBC
October
01.10.18 Safety Induction; Electrical & Cryogenic Safety 1st years 16:00 – 17:30 Physics 124
01.10.18 Introduction to Outreach 2 & 3rd years 13:00 – 14:30 TBC
02.10.18 “In the spotlight” – public speaking training (Vox Coaching) 2nd years 9:00 – 16:30 Ibrahim Ahmed/Margaret Hewitt Rooms, Reed Hall
03.10.18 CDT Metamaterials PGR conference talks All PGRs 13:30 – 17:30 Newman Red
04.10.18 Solving Problems in Wave Physics 1st years 13:30 – 14:30 Physics SCR
09.10.18 Introduction to Statistics 1st years 16:30 – 17:30 Queens LT4.2
10.10.18 CDT Metamaterials PGR conference talks All PGRs 13:30 – 17:30 Newman Red
11.10.18 Solving Problems In Wave Theory 1st years 13:30 – 14:30 Physics SCR
12.10 18 CDT Metamaterials Colloquium: Jaime Gomez Rivas, DIFFER, Eindhoven. “Surface Lattice Resonances in Arrays of Metallic Particles: From Enhanced Emission to Induced Transparency” All PGRs 12:30 – 13:30 Newman Red
15.10.18 Beyond a PhD: Professor Richard Craster, Imperial College, London All PGRs 12:30 – 13:30 tbc
15.10. 18 Beyond a PhD networking Lunch: Professor Richard Craster, Imperial College, London Optional (registration required) 13:45 – 14:30 G33
16.10.18 COMSOL training 1st years 9:00 – 16:00 G33
16.10.18 Introduction to Statistics 1st years 16:30 – 17:30 Queens LT4.2
17.10.18 COMSOL training 1st years 9:00 – 16:00 G33
18.10.18 Solving Problems in Wave Physics 1st years 13:30 – 14:30 Physics SCR
23.10.18 Introduction to Statistics 1st years 16:30 – 17:30 Queens LT4.2
24.10.18 CDT Metamaterials PGR conference talks All PGRs 13:30 – 17:30 Newman Red
25.10.18 Excellence at Interview – Day 1 (Vox Coaching) 4th years 9:00 – 17:00 Ibrahim Ahmed/Margaret Hewitt Rooms, Reed Hall
25.10.18 Solving Problems in Wave Physics 1st years 13:30 – 14:30 Physics SCR
26.10.18 Excellence at Interview – Day 2 (Vox Coaching) 4th years 9:00 – 17:00 Ibrahim Ahmed/Margaret Hewitt Rooms, Reed Hall
29.10.18 CDT PGR group meetings – kick off meeting All PGRs 14:30 – 16:00 TBC
30.10 18 Introduction to Statistics 1st years 16:30 – 17:30 Queens LT4.2
31.10 18 M13 Report Submission Deadline 2nd years
31.10.18 CDT Metamaterials PGR conference talks All PGRs 13:30 – 17:30 TBC
November
1.11.18 Solving Problems in Wave Physics 1st years 13:30 – 14:30 Physics SCR
2.11.18 CDT Metamaterials Colloquium: Miles Padgett, Glasgow University. “Better images with entangled photons” All PGRs 12:30 – 13:30 Newman Red
6.11.18 Introduction to Statistics 1st years 16:30 – 17:30 Queens LT4.2
8.10.18 Solving Problems in Wave Physics 1st years 13:30 – 14:30 Physics SCR
12.11.18 Acoustics training 2nd years 10:00 – 16:30 Physics SCR
13.11.18 Acoustics training 2nd years 9:00 – 16:00 Physics SCR
13.11.18 Magnetic Materials & Devices training 1st years 10:00 – 12:00 tbc
13.11.18 Introduction to Statistics 1st years 16:30 – 17:30 Queens LT4.2
15.11.18 Magnetic Materials & Devices training 1st years 10:00 – 12:00 tbc
19.11.18 Plasmonics training 2nd years 10:00 – 12:00

14:00 – 16:00

Physics SCR
21.11.18 Sensing & Security workshop 2nd years 14:00 – 17:00 tbc
23.11.18 Titles and Abstracts workshop 2nd years 9:30 – 10:30 Physics SCR
26.11 18 Plasmonics training 2nd years 10:00 – 12:00

14:00 – 16:00

Physics SCR
30.11.18 CDT Metamaterials Colloquium: Maria Kafesaki, IESL – FORTH, Crete. “Metamaterials for advanced electromagnetic wave control.” All PGRs 12:30 – 13:30 Newman Red
December
7.12.18 Industry Visit – IBM 3rd & 4th years arrival on 6 Dec, return late on 7 Dec IBM Daresbury

XM2 thesis submitted by Sam Shelley: The Control of Fluid Flow Using Metamaterials Concepts

Very many congratulations to Sam Shelley, EPSRC CDT in Metamaterials PGR, who recently submitted his PhD thesis titled “The Control of Fluid Flow Using Metamaterials Concepts”.  Sam was supervised by Roy Sambles (FRS), Alastair Hibbins and Simon Horsley, and previously published his work on Fluid Mobility over Corrugated Surfaces in the Stokes Regime and on Emergent propagation modes of ferromagnetic swimmers in constrained geometries. In addition, he has presented his work on Flow Control over the past 4 years through posters and talks at national and international conferences, such as the Defence and Security Doctoral Symposiums and the APS Division of Fluid Dynamics meetings. During a research stay with the CREAte group at Virginia Tech (Blackburg, Virginia, US) he enjoyed in particular the opportunity to exchange research interests, support their experimental setup and building of collaborations. Sam also shared his passion for research and science with children and adults at public engagement events such as the Sidmouth Science Festival, the Royal Cornwall Show, and the Big Bang Southwest.

We look forward to further close working relationships as he continues his research as a postdoc at the University of Exeter, and wish him good luck for his viva as the final stepping stone towards the PhD.

“The CDT has been a great experience over the past four years. Working as part of a cohort has meant that we have all been able to support each other as we have all been going through similar things. I have made some great friends during my PhD and I hope I get to work with them again.” (Sam Shelley, September 2018)

Thesis abstract

The work presented in this thesis concerns the application of concepts that are widely used in metamaterial research to the control of fluid flow. In particular surface structuring and resonance were investigated.

The initial work focussed on Stokes flow over structured surfaces. The effective boundary conditions that the structuring creates, analogous to the impedance boundary condition encountered in electromagnetism and acoustics, were examined. Exact solutions for the flow and slip length along the grooves of a family of surfaces were derived. These were compared to Finite Element Method (FEM) models and previous work valid for arbitrary structured surfaces, which was based on a perturbation expansion. Good agreement was found for all available surfaces. The previously presented solution was then also compared to results for a sinusoidal surface, finding good agreement for low aspect ratios but diverging at intermediate aspect ratios. Extending the perturbation theory beyond first order was found to improve the agreement.

To explore the concept of resonance in fluid dynamics laminar flow around a circular bluff body with an attached flexible tail was considered, investigating how the resonant behaviour of the elastic tail modified the drag and vortex shedding frequency of the body. The results were compared against the no tail case as well as a rigid tail. For short tail lengths the average drag was reduced compared to both reference cases, whilst the vortex shedding could be either enhanced or reduced. When one of the resonant frequencies of the tail matched the vortex shedding frequency of the body, the resonance motion of the tail resulted in in sharp changes to both the drag and vortex shedding frequency.

In the finally section of the thesis I describe the Particle Image Velocimetry experiments that were set up to verify the resonant flexible tail behaviour. The process by which the initial set up was upgraded is given. Results are shown for a circular bluff body being towed through the fluid. This is then extended to a circular bluff body with an attached rigid tail. Preliminary results for the flexible tail case are then presented.

ZnO nanocomposites studies – latest research results published by Zahid Hussain

The CDT in Metamaterials PGR Zahid Hussain has recently published 2 journal articles on his work with ZnO nanocomposites.  Congratulations to Zahid and the other authors.

>> See all XM² publications here: http://emps.exeter.ac.uk/metamaterials/research/publications/

XM2 thesis submitted by Timothy Spicer: Excitation of picosecond magnetization dynamics by spin transfer torque

Tim at the 6th IEEE International Conference on Microwave Magnetics (ICMM2018) where he presented his research via a talk and a poster, whilst also investing his time to support the organisers in making ICMM2018 a success.

Very many congratulations to the EPSRC CDT in Metamaterials PGR Tim Spicer, who has recently submitted his PhD thesis on “Excitation of picosecond magnetization dynamics by spin transfer torque“. Tim was supervised by Rob Hicken and Volodymyr Kruglyak. Tim is currently working on 3 more papers to publish his results in addition to his article in the Journal of Applied Physics (2016) on Time-resolved scanning Kerr microscopy of flux beam formation in hard disk write heads. He has presented  his research through posters and talks at various conferences over the past 4 years, such as the annual Magnetism conferences (2015 – 2018), the Joint European Magnetic Symposia (JEMS), and the 6th IEEE International Conference on Microwave Magnetics (ICMM2018).

We wish Tim good luck for his viva and look forward to welcoming him back as part of our growing research community  to inspire future generations in subsequent years.

“The last four years in the CDT have given have taught me invaluable skills and provided me with fantastic opportunities. One of the reoccurring highlights for me was the traveling to attend and present at conferences, despite attending quite a few I only wish I could have been to more! Through these did I not only get to see the latest research but meet with other researchers (at all levels) and discuss our respective work.

This is perhaps most epitomised by the three weeks I spent in Gothenburg University, in a very snowy February of 2017. Our collaborators very graciously lent me the use of their computing cluster (dubbed Rangnarok) for simulating magnetization dynamics, while leaving me the chance to explore the beautiful city on the weekends.

I was fortunate enough to share this journey with both very talented and very amiable scientists, both inside and outside of magnetics. Sharing music, discussing film & TV, and pub trips certainly made the PhD a more enjoyable experience, I can’t imagine doing it without any of them!

My advice to future students would be this: write everything down and try to keep a level head! Research at its best is about dealing with unexpected results for which there is no standard or established procedure, these times can be taxing but sometimes the smallest detail can tie everything together. Also having a good distraction for when you’re not in the office definitly helps!

From here I’m looking for a career in London, either within industrial R&D or analytics and software development.” (Tim Spicer, August 2018)

 

Thesis Abstract:

This thesis presents the results from investigations of ultrafast magnetization dynamics driven by pure spin currents. Spin orbit coupling in heavy metal layers – such as Tungsten, Tantalum or Platinum – allows for the generation of pure spin currents, whereby spin up and spin down electrons move in opposite directions. Hence, a flow of angular momentum can be controlled through the manipulation of charge current through a heavy metal layer. When a spin current is injected into a ferromagnet, a torque is exerted on its magnetization, with potential to induce a wide variety of ultrafast dynamics. The experimental investigation of these phenomena employed a variety of high frequency electrical techniques and time-resolved scanning Kerr microscopy (TRSKM) methods. In addition, various simulative and analytical approaches were used to gain insight into the underlying mechanisms.

Spin Hall nano-oscillators (SHNOs) have recently been shown to support a tuneable GHz spin wave `bullet’ under injection of direct current (DC), making it an exciting candidate for microwave communication applications. While the device is designed to focus DC current to within a finite active region, a new optically-based FMR technique demonstrates that the spin torques present under injection of radio frequency (RF) current are not subject to the same confinement. The competition between self-inductance and focusing within the device geometry results in a modified distribution of spin current. Further TRSKM measurements suggest that the bullet mode exhibits reduced localization within the modified torque landscape.

Devices that exploit spin currents for magnetization reversal have received interest from academia and industry for their potential use as memory elements. The perpendicular magnetic anisotropy present in Ta/CoFeB/MgO leads to lower write currents and higher thermal stability. However, ultrafast processes have not been previously observed in such devices. TRSKM measurements of Hall bar devices were compared with a macrospin model to reveal the dynamics that can be driven by a damping-like torque and Oersted field. Elements built from the same stack structure exhibited dynamics highly dependent on the amplitude and orientation of the static magnetic field, as well as motion of the domain structure for. These could also be understood in terms of the effect of an Oersted field and damping-like torque acting on the static magnetization. Measurements with a bi-polar electrical pulse demonstrated that meta-stable switching can be achieved in micron-scale elements.