| EPSRC Reference: |
GR/R74178/01 |
| Title: |
Two colour investigations of coherent and correlated processes in low dimensional semiconductor structures with FELIX |
| Principal Investigator: |
Murdin, Professor BN |
| Other Investigators: |
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| Researcher Co-Investigators: |
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| Project Partners: |
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| Department: |
Sch of Electronics & Physical Sciences |
| Organisation: |
University of Surrey |
| Scheme: |
Standard Research (Pre-FEC) |
| Starts: |
02 September 2002 |
Ends: |
01 September 2005 |
Value (£): |
93,155
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| EPSRC Research Topic Classifications: |
| Materials Characterisation |
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Summary on Grant Application Form |
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Describe the proposed research in about 200 words.Pump-probe spectroscopy has long been a powerful tool in semiconductor investigations, but is usually performed using two pulses of similar wavelgength. The recent addition of a synchronised near-IR laser system at the Dutch free electron laser facility (FELIX) provides a unique opportunity to perform new pump-probe investigations with widely different wavelengths in each pulse. We shall excite quantum wells with intense THz pulses, and measure the reflectivity spectrum of the interband pulses as a function of phase, intensity, THz frequency and applied magnetic field. This spectrum will be interpreted with the (magneto-) excitonic dynamical Franz-Keldysh effect. The same system will resonantly pump electrons from the ground state to the first excited subband in doped quantum wells. Using the interband probe we shall measure the transmission spectrum as a function of time and thus obtain the temporal k-space occupation. This will allow direct measurement of both intersubband and intrasubband electon-electron scattering. Using instead the interband pulse as the pump and the intraband (THz) pulse as the probe, we propose to measure the excited 1 s-2p transition energy spectrum as a function of resonant and nonresonant interband excitation and time. This will enable us to determine the mechanism by which excitons form and whether they are geminate. Finally the THz transient generation system at Surrey will be used for complementary experiments, specifically to perform interband pump-THz probe measurement of the lifetime of coherent collective intraband excitations.
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Key Findings |
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This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
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Potential use in non-academic contexts |
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This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
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Impacts |
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| Description |
This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk |
| Summary |
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| Date Materialised |
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Sectors submitted by the Researcher |
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This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
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| Project URL: |
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| Further Information: |
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| Organisation Website: |
http://www.surrey.ac.uk |