THz response of GaAs/AlGaAs superlattices: from classical to quantum dynamics
Autor: | K. D. Maranowski, Arthur C. Gossard, Uddalak Bhattacharya, S. J. Allen, B. J. Keay, Mark J. W. Rodwell, S. Zeuner |
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Rok vydání: | 1997 |
Předmět: |
Condensed Matter::Quantum Gases
Physics Condensed matter physics Quantum dynamics Superlattice Energy level splitting Condensed Matter::Mesoscopic Systems and Quantum Hall Effect Condensed Matter Physics symbols.namesake Stark effect symbols General Materials Science Stimulated emission Electrical and Electronic Engineering Quantum Quantum well Quantum tunnelling |
Zdroj: | Superlattices and Microstructures. 22:149-154 |
ISSN: | 0749-6036 |
DOI: | 10.1006/spmi.1996.0288 |
Popis: | We have investigated the THz response of a series of GaAs/Al x Ga 1- x As superlattices with a variety of miniband widths. The samples range from the sequential resonant tunneling limit with a very narrow miniband to superlattices with a miniband width of 20 meV. The sequential tunneling superlattices show a transition from classical rectification at frequencies below 600 GHz to quantum response above 1 THz. In the quantum regime, the I– Vs show distinct peaks due to absorption and stimulated emission of up to seven THz-photons. At high a.c. field strengths (several kV cm -1 ) the photon-assisted channels dominate the transport, leading to dynamic localization, absolute negative conductance, and gain just below the Stark splitting of the quantum well ground-states. The transition from classical to quantum behavior takes place at a frequency where ħ ο∼Γ, where Γ≈2 meV is the ground-state level width in a single quantum well. |
Databáze: | OpenAIRE |
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