Quantum coherence is an important ingredient in modern condensed matter physics as well as in emerging technologies such as quantum computation, quantum communications, and spintronics. A coherent superposition of two levels is the basis in quantum computation, and the creation and manipulation of such superposition states is currently an enormously active and diverse field of research, encompassing quantum optics, condensed matter physics, and nanoscience. We have developed a unique THz magneto-spectroscopy system, based on the technique of time-domain THz spectroscopy, ideally suited for coherent spectroscopy of solids at high magnetic fields and low temperatures. Using this system, we have observed very long-lived (up to 50 ps) THz quantum coherence in a high-mobility two-dimensional electron gas in GaAs as well as surprising ing induced-transparency phenomena in InSb.

See our recent presentation for more details: “Coherent Terahertz Dynamics of Plasmas in Solids” (invited talk at International Workshop on Advanced Materials and Devices in Osaka on August 23, 2011).

Selected Publications:

T. Arikawa, X. Wang, D. J. Hilton, J. L. Reno, W. Pan, and J. Kono, "Quantum Control of a Landau-Quantized Two-Dimensional Electron Gas in a GaAs Quantum Well Using Coherent Terahertz Pulses," Physical Review B 84, 241307(R) (2011). (abstract, full text)

X. Wang, A. A. Belyanin, S. A. Crooker, D. M. Mittleman, and J. Kono, "Interference-Induced Terahertz Transparency in a Semiconductor Magneto-plasma," Nature Physics 6, 126 (2010). (abstract, full text, news)

X. Wang, D. J. Hilton, J. L. Reno, D. M. Mittleman, and J. Kono, "Direct Measurement of Cyclotron Coherence Times of High-Mobility Two-Dimensional Electron Gases," Optics Express 18, 12354 (2010) (abstract, full text)

X. Wang, D. J. Hilton, L. Ren, D. M. Mittleman, J. Kono, and J. L. Reno, "Terahertz Time-Domain Magnetospectroscopy of a High-Mobility Two-Dimensional Electron Gas," Optics Letters 32, 13 (2007). (abstract, full text)