Klappenberger, Florian and Alekseev, K. and Renk, Karl Friedrich and Scheuerer, R. and Schomburg, Ekkehard and Allen, S. and Ramian, G. and Scott, J. and Kovsh, A. and Ustinov, V. and Zhukov, A. (2004) Ultrafast creation and annihilation of space-charge domains in a semiconductor superlattice observed by use of terahertz fields. European Physical Journal B 39 (4), pp. 483-489.
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We report an experimental study indicating ultrafast creation and annihilation of space-charge domains in a semiconductor superlattice under the action of a THz field. Our experiment was performed for an InGaAs/InAlAs superlattice with the conduction electrons undergoing miniband transport. We applied to a superlattice a dc bias that was slightly smaller than a critical bias necessary for the formation of space-charge domains caused by a static negative differential conductivity. Additionally subjecting the superlattice to a strong THz field, resulted in a dc transport governed by the formation of domains if the frequency of the field was smaller than an upper frequency limit (~3 THz). From this frequency limit for the creation and annihilation of domains we determined the characteristic time of the domain buildup. Our analysis shows that the buildup time of domains in a wide miniband and heavily doped superlattice is limited by the relaxation time due to scattering of the miniband electrons at polar optic phonons. Our results are of importance for both an understanding of ultrafast dynamics of pattern formation in nanostructures and the development of THz electronic devices.
|Institutions:||Physics > Institute of Experimental and Applied Physics > Retired Professors > Group Karl F. Renk|
|Projects:||Graduiertenkolleg Nichtlinearität und Nichtgleichgewicht|
|Subjects:||500 Science > 530 Physics|
|Refereed:||Yes, this version has been refereed|
|Created at the University of Regensburg:||Yes|
|Deposited On:||20 Mar 2007|
|Last Modified:||20 Jul 2011 21:00|