Welcome to our new cohort for 2019!

Cohort 2019. Front row, L to R: James Capers, Will Borrows, Josh Glasbey.
Back row, L to R: Joe Pitfield, James Laurenson and Leanne Stanfield

We have six new students this year- after a very busy induction week, they are eager to start work on their projects! We wish them good luck for the rewarding challenge of the next four years.

The new students are:

2019 XM² cohort Theme Project Supervisor 1 Supervisor 2 Supervisor 3
William Borrows Acoustic and Fluid-dynamical Metamaterials New materials and structures that control the propagation of acoustic radiation Steve Hepplestone David Horsell
James Capers Microwave Metamaterials Exploring the space of electromagnetic materials, with applications to antenna design Simon Horsley Alastair Hibbins
Josh Glasbey Microwave Metamaterials Manipulating the Coupling and Scattering between Surface Waves and Plane
Waves on Metasurfaces and at their Discontinuities
Alastair Hibbins Roy Sambles Richard Craster (Imperial College London)
James Laurenson Optical, Infra-red and THz Photonics and Plasmonics To Model and Manipulate Material Scatter Effects to Control the Propagation of Electromagnetic Radiation Jacopo Bertolotti Simon Horsley
Joe Pitfield Quantum Metamaterials The Search for New Materials: Using Quantum Mechanics and Theoretical Modelling to Predict New Material Structures and Phases in Constrained Systems Steven Hepplestone Misha Portnoi
Leanne Stanfield Acoustic and Fluid-dynamical Metamaterials Antenna efficiency and match manipulation using metamaterials Alastair Hibbins Roy Sambles

Many members of staff and their fellow students joined them for an all CDT Get Together:

Staff and students from CDT

Induction Week 2019 get together in Northcott Theatre

Natalie Whitehead submits her thesis!

Congratulations to PGR Natalie Whitehead, who has just submitted her thesis on ‘Making The Grade: Generating and Controlling Spin Waves with a Graded Refractive Index’. Her supervisors were Prof. Volodymyr Kruglyak, Dr. Thomas Philbin and Dr. Simon Horsley.

During her degree, Natalie has been prolific in her Outreach work. As well as being part of Metabuddies, the CDT’s schools outreach scheme, she has had led and taken part in many outreach events and workshops, a particular favourite being a yearly Inspiring Science Lecture at Exeter College

Last year, Natalie spent a month with University of Manitoba, Canada, working with Prof. Bob Stamps on understanding the principles of ‘Coherent Perfect Absorption’ theoretically for both a mirror and a 2-way input, trying to implement for spin waves. Natalie said this was one of the highlights of her degree and that she learned a lot, as well as enjoying her visit to Canada.
She won Best Poster Award for poster “Theory of Spin Wave Emission from a Bloch Domain Wall” at JEMS 2016, and again in Magnonics 2018. Other achievements include nominations for the University of Exeter’s 41 Women Campaign 2015.

Natalie’s publications include:

Natalie presented at the following conferences:

  • January 2019- Intermag / MMM Conference 2019, Washington DC, USA (presentation on ‘Graded Index Lenses for Spin Waves), authors N.J. Whitehead, T.G. Philbin, S.A.R. Horsley, V.V. Kruglyak
  • July 2018-  ICMFS 2018, Santa Cruz, USA (poster on ‘A Luneburg Lens for Spin Waves, and  Theory of Linear Spin Wave Emission from a Bloch Domain Wall’), authors N.J. Whitehead, T.G. Philbin, S.A.R. Horsley, V.V. Kruglyak (+ A. N. Kuchko for latter)
  • July 2018-  ICM 2018, San Fransisco, USA (poster on ‘A Luneburg Lens for Spin Waves, and  Theory of Linear Spin Wave Emission from a Bloch Domain Wall’), authors N.J. Whitehead, T.G. Philbin, S.A.R. Horsley, V.V. Kruglyak (+ A. N. Kuchko for latter)
  • June 2018- SolSkyMag 2018, San Sebastian, Spain (poster on ‘A Luneburg Lens for Spin Waves’), authors  N.J. Whitehead, T.G. Philbin, S.A.R. Horsley, V.V. Kruglyak
  • June 2018- International Advanced School on Magnonics 2018, Kiev, Ukraine (poster on ‘Graded Index Lenses for Spin Waves’), authors N.J. Whitehead, T.G. Philbin, S.A.R. Horsley, V.V. Kruglyak
  • June 2018- ICMM 2018,  Exeter, UK (30 minute talk on ‘Graded Index Lenses for Spin Waves’), authors N.J. Whitehead, T.G. Philbin, S.A.R. Horsley, V.V. Kruglyak
  •  April 2018- Magnetism 2018, Manchester, UK (poster on ‘ Theory of Linear Spin Wave Emission from a Bloch Domain Wall’- awarded ‘best poster’ at conference), authors N.J. Whitehead, T.G. Philbin, S.A.R. Horsley, A.N. Kuchko, V.V. Kruglyak
  •  August 2017- Magnonics 2017, Oxford, UK (poster on ‘Theory of Linear Spin Wave Emission from a Bloch Domain Wall’), authors N.J. Whitehead, T.G. Philbin, S.A.R. Horsley, A.N. Kuchko, V.V. Kruglyak
  •  July 2017-  MagIC 2017, Poznan, Poland (presentation on ‘Theory of Linear Spin Wave Emission from a Bloch Domain Wall’), authors N.J. Whitehead, T.G. Philbin, S.A.R. Horsley, A.N. Kuchko, V.V. Kruglyak
  •  August 2016- JEMS 2016, Glasgow, UK, (poster on ‘Theory of Spin Wave Emission from a Bloch Domain Wall’, one of the ten ‘Best Posters’ out of over 500 submitted), authors N.J. Whitehead, T.G. Philbin, S.A.R. Horsley, A.N. Kuchko, V.V. Kruglyak
  •  June 2016- International Advanced School on Magnonics, Exeter, UK (poster on ‘Theory of Spin Wave Emission from a Rectangular Anisotropy Defect’, also host and co-organiser of conference), authors N.J. Whitehead, T.G. Philbin, S.A.R. Horsley, A.N. Kuchko, V.V. Kruglyak
  •  April 2016-  Magnetism 2016, Sheffield, UK (poster on ‘Theory of Spin Wave Emission from a Rectangular Anisotropy Defect’), authors N.J. Whitehead, T.G. Philbin, S.A.R. Horsley, A.N. Kuchko, V.V. Kruglyak

Next, Natalie is working on the ambitious task of opening a STEM + Art (“STEAM”) Science Centre in Exeter. She says:

“At the Exeter Science Centre, we aim to connect the science research institutions of the South West with the general public, providing an inspiring space for all. This space will be filled with engaging, hands-on exhibits which explain the awesome science that’s going on in the region, particularly around the themes of ‘Global Challenges’. Science will be interweaved with art throughout, to express and mirror the underlying creative process involved in every scientific endeavour.

 

Our goal is to educate and inspire the general public about science through our guided exhibits, regular public talks, events, and collaborations with CoachBright and other educational organisations. We want to give the public the tools, the inspiration and the motivation to make a difference in the world. “

More information on this exciting project can be found at exetersciencecentre.org.

 

PGR Joaquin Faneca at training school on Emerging Technologies for 5G Networks

Joaquin Faneca was recently in Greece (Thessaloniki) attending a training school on Emerging Technologies for 5G networks.  He received The EUIMWP (CA 16220) COST Action GRANT to cover attendance costs.

Joaquin was presenting the work he has developed between the University of Southampton and University of Exeter, about reconfigurable silicon photonic integrated circuits for future applications in 5G.

Joaquin says of his work:

My conclusions are optimistic and I thinks that this technology can make use of the photonic integrated circuits for filtering and to play a role in part of the circuits they are developing in the technology 5G . There is still a lot of work regarding the losses that the integrated circuits are playing when you integrated them with the rest of the circuitry of the 5G technology.

New Publication: Novel Au–SiO2–WO3 Core–Shell Composite Nanoparticles for Surface‐Enhanced Raman Spectroscopy with Potential Application in Cancer Cell Imaging

 

Congratulations to third year PGR Pablo Martinez Pancorbo for his latest publication- a paper on Novel Au–SiO2–WO3 Core–Shell Composite Nanoparticles for Surface‐Enhanced Raman Spectroscopy with Potential Application in Cancer Cell Imaging , published this week in Advanced Functional Materials.

Abstract

With the rapid development of nanotechnology during the last decades, the ability to detect and control individual objects at the nanoscale has enabled us to deal with complex biomedical challenges. In cancer imaging, novel nanoparticles (NPs) offer promising potential to identify single cancer cells and precisely label larger areas of cancer tissues. Herein, a new class of size tunable core–shell composite (Au–SiO2–WO3) nanoparticles is reported. These nanoparticles display an easily improvable ≈103 surface‐enhanced Raman scattering (SERS) enhancement factor with a double Au shell for dried samples over Si wafers and several orders of magnitude for liquid samples. WO3 core nanoparticles measuring 20–50 nm in diameter are sheathed by an intermediate 10–60 nm silica layer, produced by following the Stöber‐based process and Turkevich method, followed by a 5–20 nm thick Au outer shell. By attaching 4‐mercaptobenzoic acid (4‐MBA) molecules as Raman reporters to the Au, high‐resolution Raman maps that pinpoint the nanoparticles’ location are obtained. The preliminary results confirm their advantageous SERS properties for single‐molecule detection, significant cell viability after 24 h and in vitro cell imaging using coherent anti‐stokes Raman scattering. The long‐term objective is to measure SERS nanoparticles in vivo using near‐infrared light.

New Publication: Metasurface bilayer for slow microwave surface waves

Congratulations to fourth year PGR Julia de Pineda Gutiérrez, whose paper ‘Metasurface bilayer for slow microwave surface waves’ was recently published in Physical Review B. Julia’s previous publications include Microwave edge modes on a metasurface with glide symmetry and Hexagonal symmetry metasurfaces for broadband antenna applications. Julia’s thesis is on exploration of beam shaping at microwave frequencies using metasurfaces and metamaterials .

Abstract for ‘Metasurface bilayer for slow microwave surface waves’ below.

Abstract

We present a simple two-layer discontinuous crossed metal-strip array that guides microwaves having very high phase and group indices. The strips are arranged on a square lattice with a two-layer unit cell. The difference in this structure resides in the length of the metal strips, which extend to several unit cells. This work focuses on the isotropic wave dispersion at the lower frequencies. In addition, two of the higher-frequency bands give rise to a very strong negative dispersion, and strong beaming occurs, which can be tailored easily by modifying the relative orientation of the layers.

 

New Publication: 2D WS2 liquid crystals: tunable functionality enabling diverse applications

Ben Hogan

Congratulations to PGR Ben Hogan, who has just published a paper on ‘2D WS2 liquid crystals: tunable functionality enabling diverse applications’  in Nanoscale.

Ben says of his paper:

This paper describes the first observation of a liquid crystal phase for dispersions of two-dimensional tungsten disulfide particles in organic solvents. We detail the synthesis methods used to obtain the liquid crystals. We then characterise them, observing interesting and unexpected dichroism properties some of which can be controlled by the application of a magnetic field. We then demonstrate the first applications of the liquid crystals by producing highly uniform thin films of tungsten disulfide, which are then shown to be useful for developing future terahertz modulation devices. This paper represents the culmination of two and a half years of hard work, and involved collaborations with ITMO University (Russia) and Massachusetts Institute of Technology (USA)

Ben’s publications this year include Photoluminescence from NV− Centres in 5 nm Detonation Nanodiamonds: Identification and High Sensitivity to Magnetic Field and Transmission Properties of FeCl3-Intercalated Graphene and WS2 Thin Films for Terahertz Time-Domain Spectroscopy Applications.

Please see below for the abstract of ‘2D WS2 liquid crystals: tunable functionality enabling diverse applications’.

Abstract

The first observation of liquid crystalline dispersions of liquid phase-exfoliated tungsten disulfide flakes is reported in a range of organic solvents. The liquid crystals demonstrate significant birefringence as observed in the linear and circular dichroism measurements respectively. In particular, linear dichroism is observed throughout the visible range while broad-band circular dichroism can be observed in the range from 500–800 nm. Under an applied magnetic field of ±1.5 T the circular dichroism can be switched ON/OFF, while the wavelength range for switching can be tuned from large to narrow range by the proper selection of the host solvent. In combination with photoluminescence capabilities of WS2, this opens a pathway to a wide variety of applications, such as deposition of highly uniform films over large areas for photovoltaic and terahertz devices.