Abstract-Disturbing the coherent dynamics of an excitonic polarization with strong terahertz fields

M. J. Drexler, R. Woscholski, S. Lippert, W. Stolz, A. Rahimi-Iman, and M. Koch

https://journals.aps.org/prb/abstract/10.1103/PhysRevB.90.195304

We present a paper based on combining four-wave mixing and strong fields in the terahertz frequency range to monitor the time evolution of a disturbed excitonic polarization in a multiple quantum well system. Our findings not only confirm a lower field-dependent ionization threshold for higher excitonic states, but furthermore provide experimental evidence for intraexcitonic Rabi flopping in the time domain. These measurements correspond to the picture of a reversible and irreversible transfer as previously predicted by a microscopic theory.

DOI: http://dx.doi.org/10.1103/PhysRevB.90.195304

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Abstract-Disturbing the coherent dynamics of an excitonic polarization with strong terahertz fields

M. J. Drexler, R. Woscholski, S. Lippert, W. Stolz, A. Rahimi-Iman, and M. Koch

https://journals.aps.org/prb/accepted/c907aY1bEf71ff4532829ec048ac14177c73bb7f9

We present a study based on combining Four-Wave-Mixing (FWM) and strong fields in the terahertz frequency range (THz) to monitor the time-evolution of a disturbed excitonic polarisation in a multiple quantum well system. Our findings not only confirm a lower field-dependent ionisation threshold for higher excitonic states but furthermore provide experimental evidence for intra-excitonic Rabi flopping in the time domain. These measurements correspond to the picture of a reversible and irreversible transfer as previously predicted by a microscopic theory.

Abstract:Ionization of coherent excitons by strong terahertz fields

B. Ewers, N. S. Köster, R. Woscholski, M. Koch, and S. Chatterjee 
Faculty of Physics and Materials Sciences Center, Philipps-Universität Marburg, Renthof 5, D-35032 Marburg, Germany

G. Khitrova and H. M. Gibbs 
College of Optical Sciences, The University of Arizona, 1630 E. University Boulevard, Tucson, Arizona 85719-0094, USA

A. C. Klettke, M. Kira, and S. W. Koch 
Faculty of Physics and Materials Sciences Center, Philipps-Universität Marburg, Mainzer Gasse 33, D-35032 Marburg, Germany

Received 7 December 2011; revised 16 January 2012; published 6 February 2012

The interaction of coherent excitons with intense, single-cycle terahertz (THz) pulses is investigated. A significant bleaching of the 1s-exciton resonance develops into a splitting of the absorption peak and the emergence of pronounced wings with increasing THz field strength. A quantum-mechanical many-body analysis attributes the experimental observations to a transition from excitonic Rabi flopping to multi-THz-photon ionization and the population of optically dark exciton states with high quantum numbers.

©2012 American Physical Society

URL:

http://link.aps.org/doi/10.1103/PhysRevB.85.075307

DOI:

10.1103/PhysRevB.85.075307

PACS:

78.67.De, 42.65.Re, 78.47.D-