Regensburg 2002 – wissenschaftliches Programm

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HL: Halbleiterphysik

HL 3: Heterostrukturen I

HL 3.6: Vortrag

Montag, 11. März 2002, 11:45–12:00, H14

Superlattice with hot electrons: a new approach to Bloch oscillators — •Dmitri A. Ryndyk^1,2, Joachim Keller¹, and Ekkehard Schomburg³ — ¹Institut f"ur Theoretische Physik, Universit"at Regensburg — ²Institut for Physics of Microstructures RAS, Nizhny Novgorod, Russia — ³Institut f"ur Experimentelle und Angewandte Physik, Universit"at Regensburg

We consider a semiconductor superlattice biased by a dc electric field when additional hot electrons are injected into the miniband. We find that the dc differential conductivity, which at high bias fields normally is negative, now can be positive and hence low-frequency domain formation will be suppressed. At the same time the ac differential conductivity is negative at high frequencies above the Bloch frequency making the excitation of plasma-Bloch ways possible. This opens a new way to operate Bloch oscillators at THz frequencies.