Cyclotron resonance photoconductivity of a two-dimensional electron gas in HgTe quantum wells

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• 作者：Ze-Don Kvon ; Sergey N. Danilov ; Nikolay N. Mikhailov ; Sergey A. Dvoretsky ; Wilhelm Prettl ; Sergey D. Ganichev
• 关键词：Cyclotron resonance ; Gapless semiconductor ; Heterostructure ; HgTe quantum wells
• 刊名：Physica E
• 出版年：2008
• 出版时间：April 2008
• 年：2008
• 卷：40
• 期：6
• 页码：1885-1887
• 全文大小：169 K

文摘

Far-infrared cyclotron resonance photoconductivity (CRP) is investigated in HgTe quantum wells (QWs) of various widths grown on (0 1 3) oriented GaAs substrates. It is shown that CRP is caused by the heating of two-dimensional electron gas (2DEG). From the resonance magnetic field strength effective masses and their dependence on the carrier concentration is obtained. We found that the effective mass in each sample slightly increases from the value (0.0260±0.0005)<i>mi>₀ at <i>Ni>_s=2.2×10¹¹ cm⁻² to (0.0335±0.0005)<i>mi>₀ at <i>Ni>_s=9.6×10¹¹ cm⁻². Compared to determination of effective masses by the temperature dependence of magnitudes of the Shubnikov-de Haas (SdH) oscillations used so far in this material our measurements demonstrate that the CRP provides a more accurate (about few percents) tool. Combining optical methods with transport measurements, we found that the transport time substantially exceeds the cyclotron resonance lifetime as well as the quantum lifetime which is the shortest.