We have developed a coherent time-domain THz magneto-spectroscopy system. It can be used for measuring the refractive index, complex conductivities, and cyclotron resonance of different semiconductor structures as well as for investigating fundamental physical phenomena. As a first application, we have carried out time-domain cyclotron resonance studies of an ultrahigh-mobility two-dimensional electron gas at low temperatures. We observed coherent cyclotron resonance oscillations that persist as long as ∼ 50 ps. We show that the basic physics of these oscillations can be described as the free induction decay of a coherent superposition between the lowest unfilled Landau level and the highest filled Landau level prepared by an incident THz pulse. Using the 0 Tesla data as a reference, we successfully extracted the real and imaginary conductivities for different magnetic fields in the frequency domain. Finally, I will discuss a few future experiments that will be performed with this novel system.
| Identifer | oai:union.ndltd.org:RICE/oai:scholarship.rice.edu:1911/17929 |
| Date | January 2006 |
| Creators | Wang, Xiangfeng |
| Contributors | Kono, Junichiro |
| Source Sets | Rice University |
| Language | English |
| Detected Language | English |
| Type | Thesis, Text |
| Format | 98 p., application/pdf |
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