PhD projects 2017-18
There are three routes currently available in the group:
- We are currently seeking applicants for the new Centre for Doctoral Training in Condensed Matter Physics for a diverse set of projects.
- Fully funded 3.5/4 year studentships are available for 2017 through Doctoral Training Partnerships (DTPs), formally known as DTAs.
- A fully funded 3.5 year studentship is available for 2017 as part of an ERC research grant: ERC_PhD_Advert_2018 (PDF, 426kB).
Current projects in the group
High Pressure Studies on Superconductors (Dr Friedemann)
High pressure research provides vital information in the challenge to understand superconductors: It allows highly systematic studies tuning the properties of one sample without introducing disorder or breaking symmetries. As pressure is easily modelled our research offers decisive input for theoretical models.
This project aims at studying the new record superconductor H3S with a transition temperature of more than 200 K . A combination of magnetic and electrical measurements will be used to investigate the mechanism of high-temperature superconductivity. We will make use of novel pressure techniques like the gold patterned gemstone anvils in the picture for electrical transport studies. Measurements will be performed both at the HH Wills Laboratory in Bristol as well as at international high-field facilities.
Quantum Electronic Order (Prof Hayden)
Strong correlations between electrons in solids can lead to some spectacular effects, perhaps the most astonishing of which is high temperature superconductivity. The field of correlated electron systems has been made rich and exciting by a series of experimental discoveries over the last two decades. In this project you will investigate electronic order and the associated collective excitations. The aim of the research is to explain physical properties of materials such as superconductivity, electronic nematic order or charge order by measuring the electronic correlations. The work involves neutron and x-ray scattering, laboratory measurements using high magnetic fields and low temperatures, crystal growth and theoretical modelling. We carry out experiments at synchrotrons and neutron facilities around the around the world.
Two examples of materials which we are presently working on are the large temperature superconductor YBa2Cu3O6+x where we have recently observed charge order  and the 4d oxide metals Sr2RuO4 and Sr2Ru3O7 (see Figure).
Email Stephen Hayden for more information.
Field effect gating of correlated thin films and surfaces (Dr Bell)
Transistors have revolutionized the world of computers. For basic research they are also extremely powerful devices to study correlated materials which are sensitive to the electron density in the system. The electrostatic field effect used in transistors reversibly adds and removes electrons from a thin film or surface, and can tune the groundstate of the material. A recent trend is the use of ionic liquids as gates: the large capacitance of the induced Helmholtz layer and high breakdown electric fields means that they can dope far higher carrier densities than conventional gate materials. Several groups around the world have established this technique to make novel transistors, demonstrating control of superconductivity and magnetism at the surfaces of crystals or in thin films over a range that cannot be achieved by other means. We will use this technique to examine correlated materials, searching for new groundstates at field-effect doped surfaces.
Email Dr Chris Bell for more information.
Heavy Electron Compounds (Dr Friedemann)
Heavy Fermion compounds are made from rare earth elements and other metals. The rare earth elements contribute local magnetic moments which interact with conduction electrons. It is exactly this interaction which makes heavy fermion systems very interesting.
The local moments form composite quasiparticles that behave like electrons but with largely increased masses up to several thousand times the bare electron mass – thus the name heave fermions. They provide model systems for many questions central to solid state physics and beyond like high-temperature superconductivity, strong correlations, and correlated topology. They can be tuned in a very controlled way and thus allow detailed insight into strongly correlated behaviour.
Current projects investigate novel heavy fermion compounds with lower dimension and surface states. We employ measurements of the electrical resistance and Hall effect to study these materials and their electronic structure.
Email Dr Sven Friedemann for more information.
How to apply
Contact us for opportunities at the Centre for Doctoral Training.
For the DTP projects, contact the project supervisor.