My research interests are centred in the field of low-temperature
superconducting and magnetic devices with particular focus
on nano-scale devices.
Conventional superconductivity and ferromagnetism are generally considered competing
quantum phenomena – the former associated with electron attraction in an anti-parallel spin
orientation to form Cooper pairs, while the latter encourages the parallel alignment of
electron spins. This mutual antagonism at the most fundamental level would appear, at first
sight, to preclude the interaction of such materials for any realistic physical parameters.
In practice there is, in fact, a very rich range of fascinating and novel phenomena that can
be observed if the experimental difficulties can be overcome. The principal challenges are
that the energy and length scales with which the experimentalist must work are small and the
study of superconductors and ferromagnets in close proximity has really only begun in the
last few years. At the same time, there has been a rapid increase in interest in the
manipulation of electron spin in electronic structures to harness new functionality – leading
to the field of spintronics. The time is now ripe for these fields to be combined, to
encompass the novel and exotic properties of the superconductor-ferromagnet hybrid with
functionality offered by the active control of electron spin.
Since August 2006 I have been a
lecturer and an EPSRC Advanced Research Fellow in the
Condensed Matter Physics Group, in the
School of Physics and Astronomy at the
University of Leeds. I currently have three PhD Students:
Alex Jenkins, working for me on the proximity effect between domain walls and superconductors;
Jim Webb, working on Cross-Andreev Reflection; and Matt Newman, working on Graphene
Superconding Josepshson Junctions.
Before I moved to Leeds, I worked as a Post-Doctoral Research Associate
in the Device Materials Group within
the Department of Materials Science and IRC in Nanotechnology, University
of Cambridge. My work was funded as part of the UK
Engineering and Physical Sciences Research Council grant
on "Resolved Spin-Polarisation Spectroscopy For Improved
Characterisation Of Spintronic Materials" in conjunction
with Imperial College, London.
In 1998 I gained my PhD which was in quasiparticle
and phonon trapping in superconducting particle detectors.
This work was part of our development of tunnel junction
devices for X-ray detectors for applications in astronomy.
Prior to this I read Materials Science and Metallurgy,
gaining a BA in the summer of 1994. As part of my undergraduate
work, I carried out projects on carbon nanotubes and, in
my first encounter with superconductivity, quasiparticle
|My research has focused for a number of
years on the fabrication and characterisation of novel nanoscale
superconducting and magnetic devices using a focused
ion beam (FIB) system. I have expertise in thin
film deposition, cleanroom based micro-fabrication, and cryogenic
electrical measurement and characterisation techniques.
In order to carry out my research – and in support
of the other projects within my research group – I
have set up and developed a number of advanced measurement
systems for the characterisation of device structures produced
right across the work of my research group. In doing this
I have made a significant contribution to the research activity
of the whole laboratory, and my work has led to a continuing
record of high quality and timely publications.
I applied my experience in fabricating devices
with the FIB to the recently discovered superconductor
magneisum diboride and to produce the first all-MgB2 thin
film single Josephson junctions and, to date, one of the
best performing MgB2 thin film SQUIDs. I have continued
to work on MgB2, both in basic science and in fabricating
improved junctions as part of the established programme
on masked ion damage junctions.
A substantial part of my work in the Device Materials
group has been the construction and programming of various
experimental rigs for use within the group. This is mainly
carried out using National Instruments LabVIEW,
and I maintain a separate
page with some examples and demonstrations of my code.