High field cyclotron resonance and the electron effective masses in AlAs

Xz−Xxy crossover in a two-dimensional electron gas in AlAs

“…In optically detected magnetic resonance measurements it is found that in these SLs, the lowest X state changes from X~ character to X= character ff the AlAs thickness becomes smaller than 55 A [1]. Cyclotron resonance measurements and recent Shubnikov-de Haas measurements [2][3][4] revealed the density of states (DOS) effective masses of these states, mx~, = ~ =0.5-0.6mo and mx~=mt=0.3mo. Apparently, for wide wells, the energy position of the X~ and X= states is reversed with respect to what is expected from the binding masses mt and ml ( ~ 1.0nto).…”

Energy-Band Structure: Electron and Hole Effective Masses

“…113125 " 38 We have already shown in Fig. 8.12 the valence-subband structures of ALjGa^As/GaAs quantum wells consisting of 15 GaAs monolayers with (100), (111), and (110) orientations, as calculated by Houng et al 132 As can be seen in this figure, the valence-subband structures for different orientations are apparently different.…”

“…[Note that mass determination from carrier-transport analysis is less accurate than that from Faraday rotation.] More recently, Miura et al 38 have measured far-infrared cyclotron resonance in n-AJAs grown by molecular-beam epitaxy on GaAs substrate in pulsed high magnetic fields up to 150T. The effective masses they determined from these measurements are m,x=(0.25±0.01)m 0 and m ix =(0.88±0.07)m 0 .…”

Calculation of electron effective masses in AlAs

“…The electron effective masses were directly measured by Miura [7] using high field cyclotron resonance in 1991. A prominent resonance peak which corresponds to the effective mass of…”

“…Sasaki et al [lo] pointed out that this disagreement was due to the interpretation of the observed cyclotron resonance peaks which correspond to the effective mass of m, = (0.44 -0.5)mo. Smith et al [5] and Miura [7] regarded the peak as due to the heavier effective mass of based on the field direction dependence of the observed cyclotron mass. On the other hand, Goiran et al [9] observed an extra resonance peak corresponding to the effective mass of 1.05m0, and regarded this as m. Sasaki et al [lo] obtained a transverse effective mass of mt = (0.16 I I C 0.07)mo for the AlAs X point in their magneto-photoluminescence study.…”