Our Experimental Condensed Matter and Nanoscience research involves seven groups:
Nanometre scale structures and nanostructured materials play an increasingly important role in a wide range of scientific disciplines, ranging from solid-state physics through to molecular biology.
Research interests reflect this multidisciplinary and involve intra- and inter-university collaborations with groups in Chemistry, Biomedical Sciences and Pharmaceutical Sciences. Scanning probe microscopes are used extensively by the group.
Extensive in-house semiconductor growth and fabrication facilities, including four MBE systems and nanolithography, provide the basis for wide-ranging studies of III-V arsenide and nitride semiconductor materials and devices.
We are investigating novel alloys, self-organised quantum dots, superlattices and nanostructures using techniques including electrical transport, quantum tunneling, ultra-fast optical spectroscopy, phonon spectroscopy and imaging, and capacitance and magnetic force scanning probe microscopy.
Granular materials are extremely unusual in that they can simultaneously display properties normally associated with solids, liquids and gases, together with other properties which are uniquely on there own. Our research aims to investigate the dynamical behaviour of various granular systems using a combination of experimentation, numerical simulations and analytical studies.
We use strong magnetic fields, up to 17 Tesla, generated by superconducting magnets to levitate water and biological organisms such as plants and bacteria. Within a magnetically levitated object, the force of gravity is balanced by a magnetic force at the molecular level. This means we can investigate the effects of weightless conditions, without needing a spaceship.
We can also use the magnetic field to effectively increase the force of gravity, or to apply "differential" gravity to mixtures, such as granular materials, to achieve separation.
Nanoelectromechanical Systems (NEMS)
NEMS can be regarded as a natural continuation of a process of miniaturisation which initially led to the development of microelectromechanical systems (MEMS) and as such are likely to find a very wide range of applications in nanotechnology. A number of very promising prototype NEMS devices have already been developed. In particular, intensive effort has been devoted to developing detectors of mass, spin and charge, based on high frequency mechanical resonators. On a more fundamental level, nanomechanical resonators, with frequencies up to the GHz range, have been identified as having great potential for probing the transition from quantum to classical regimes. The fundamental limits set by quantum mechanics on the sensitivity with which a resonator's position can be monitored have been known for some time, but it is only very recently, using nanomechanical systems, that experiment has come close to reaching them. Extending these ideas to even higher frequencies, ultrafast optical methods are being used to probe vibrations of nanostructures up to THz frequencies. This has potential applications in THz acoustoelectric devices for communications and spectroscopy.
Nuclear Magnetic Resonance; and Ultra-Low Temperature Physics
Activities in this field focus on the production and exploitation of hyperpolarised species for medical and materials sciences. The work is undertaken using 2 dilution refrigerators combined with NMR spectrometers and a low field MRI scanner. Low temperatures and high magnetic field are used to induce high nuclear spin polarisation is MRI active isotopes such as C13 that can then be used to enhance the contrast in MRI.
Further information on all of these areas can be found on the Experimental Condensed Matter and Nanoscience research website.