THz Radiation Source through Periodically Modulated Structures.
Interim rept. no. 5, Nov 96-Feb 97
TECHNISCHE UNIV VIENNA (AUSTRIA) INST FUER FESTKOERPERELEKTRONIK
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While the previous period was dedicated to the study of combinations of different superlattices using an advanced technique of hot electron spectroscopy, we have concentrated our activities in the 5th period of this project on the study of quantum wires. We could demonstrate for the first time that the magnetophonon effect can be used to characterize quantum wires with a very low number of subbands occupied. In this case the Shubnikov-deHaas technique cannot be applied any more. The development of this technique is an important step forward in the realisation of high quality quantum wires. High quality wires with 1 to 3 meV subband splittings were produced. These quantum wires with subband splittings in the THz region are one possible candidate for a coherent source in this frequency range. Future work will concentrate on new methods to produce quantum wires with tunable subband spacings. Novel side gate structures are under investigation at present together with V-groove overgrowth techniques. We hope to achieve subband spacings close to 10 meV tunable over a wide range.
- Solid State Physics