Semiconductor physics PhD projects
Our large and vibrant group has PhD students involved in research on a wide variety of topics in the area of semiconductor nanostructures. We have strong activities in both fundamental physics (eg. control of light-matter interactions) and applied research (e.g. new laser sources). In addition to being very well equipped, the group also has unrivalled access to state of the art semiconductor structures from the National Centre for III-V Technologies at Sheffield.
For general enquiries contact Prof Maurice Skolnick, m.skolnick@shef.ac.uk.
Further details of our research areas are given on our web pages: http://ldsd.group.shef.ac.uk
Enquiries are invited regarding the following PhD positions. At any particular time there may also be associated postdoc positions:
Semiconductor quantum optical circuits
As a result of a new (January 2012), five year large grant award from the UK funding agency, EPSRC, several positions are available in highly topical areas of semiconductor physics and optics research. These include the physics of the first semiconductor quantum optical circuits, novel methods for spin readout and new types of single photon sources. All topics have the opportunity for advanced fabrication of nanoscale structures, and involve participation in research at the leading edge of semiconductor physics and photonics.
Both experimental and theoretical projects are available, starting in October 2012.
For more information please contact Prof Maurice Skolnick, m.skolnick@shef.ac.uk
Electron and nuclear spin effects in nano-structured semiconductor materials
Recent advances in semiconductor nano-technology lead to a new generation of robust controllable structures where manipulation of the matter is possible on a single electron level. The electron charge is not the only practical solution as a means of encoding information using novel nano-devices. In semiconductor quantum dots to be studied in this project, an increasingly important role will be played by the electron quantum degrees of freedom. A particular emphasis in this project will be placed on the electron spin, offering a variety of very attractive properties for control. Additional flexibility in dealing with quantum information will be gained from manipulation of spins of lattice nuclei of which the nano-structure is composed.
The start date is 1st October 2012. All formal and informal inquiries: Dr Alexander Tartakovskii, a.tartakovskii@shef.ac.uk.
Further information about the group: see http://www.ldsd.group.shef.ac.uk/qdots/spin.php
Green photonics using photonic crystals
Present day telecommunications systems consume large amounts of energy. One very promising route to overcome this major energy cost is to employ photonic crystal technology to achieve all optical switching operating at low light levels. Photonic Crystals are structures with periodicity on the order of the wavelength of light, which allow control of the flow of light, its storage and switching. The student will study the optical properties of cavities and waveguides fabricated using this advanced technology. Particular emphasis will be placed on the study of cavities for photon storage fabricated in the crystal: the long photon lifetimes in such cavities have high potential to lead to very low power switching phenomena, providing a very favourable route towards the overall aims of the project.
For more details contact Prof Maurice Skolnick, m.skolnick@shef.ac.uk
Surface plasmon quantum cascade lasers
Supervisor: Dr Luke Wilson
The quantum cascade laser (QCL) is one of the most exciting semiconductor devices to be developed in recent years, capable of high performance levels and unprecedented wavelength agility across the mid-IR and THz wavelength ranges. A PhD student is sought to develop highly novel surface-plasmon (SP) QCLs, i.e. devices where the waveguide mode is a surface-plasmon polariton excitation. SPs are waves that propagate at the interface between two materials with dielectric constants of opposite signs, such as the interface between a semiconductor and a metal. It turns out that waveguides based on SPs exhibit low losses at the very long wavelengths emitted by QCLs. By patterning the QCL surface metal with a periodicity close to the emission wavelength a whole new range of QCL plasmonic devices may be produced with unique functionalities and applications in trace gas sensing, detection of biomolecules and near field imaging.
New semiconductor materials for quantum cascade lasers
Supervisor: Dr John Cockburn
A PhD student is sought in this new area of semiconductor laser research. Our group has established a substantial track record in this area, with a number of world firsts over the last few years. Our position in the field is substantially enhanced by the wide ranging crystal growth and device fabrication capabilities at Sheffield, together with excellent techniques for device measurement and for study of new physics. This new PhD position will be concerned in particular with the investigation of quantum cascade lasers in new materials systems with the aim of extending operation into new wavelength ranges, and achieving significant enhancement to performance of present day lasers.
Semiconductor lasers for telecommunications applications
Supervisor: Prof David Mowbray
A PhD student is sought in a highly topical area of semiconductor device research, namely the study of semiconductor lasers which operate in the telecommunications band of 1.3 to 1.5 microns. This is an area where Sheffield has achieved major success, with novel lasers based on semiconductor quantum dots exhibiting record properties. The studentship will be concerned with the investigation of the physical mechanisms controlling laser performance, still poorly understood, and with the study of new structures aimed at increasingly long wavelength. Our position in the field is substantially enhanced by the wide ranging crystal growth and device fabrication capabilities at Sheffield, together with excellent techniques for device measurement and for study of new physics.