Far-infrared optically detected cyclotron resonance observation of quantum effects in GaAs

Abstract

For the first time optically detected cyclotron resonance (ODCR) has been demonstrated using a CO, pumped far-infrared (FIR) laser instead of mircowaves. Both the electron and the light-hole cyclotron resonances have been observed in GaAs, as well as the 1 S to 2p + impurity transitions. Valence band quantum effects, well known in Ge, are resolved directly for the first time in GaAs and the electron cyclotron resonances show strong spin doublet in the highest quality MBE samples. The technique has remarkable resolution and sensitivity at low temperatures and, by constrast with other techniques that have been reported, we also observe the n = 1 to 2 (polaron shifted) and higher spin doublet split resonances at helium temperatures and with low FIR laser power. The conduction band results are analysed on the five-band model and the implications of this model on the valence band results are discussed. We have determined the valence band inverse mass parameters to be: ;' , = 7.5, 7, = 2.6, y3 = 3.1, K = 1.0.

An optically detected cyclotron resonance study of bulk GaAs

“…For FIR wavelengths of 70 and 118 urn, a high-field tail to the free-electron cyclotron resonance peak was seen (figure 9). These have been observed previously in both ODCR [2,3]…”

Terahertz Dynamics of Excitons in GaAs/AlGaAs Quantum Wells

“…This PL quenching is consistent with the interpretation that the FIR radiation heats photoinjected electrons and holes, which in turn heat and decrease peak emission from luminescing excitons [6]. Numerous experiments have optically detected cyclotron resonance [7][8][9][10][11][12][13], and impurity transitions [14,15] in various bulk semiconductors and quantum heterostructures. The equivalence of ODR and conventional transmission techniques in determining the frequency of absorption resonances has been shown clearly (for example, see [10,11]).…”

Effects of band offset and nonparabolicity on the effective mass of two-dimensional electron gases in modulation-δ-dopedGa0.47InDai1, Chen2, Lo3 1997Phys. Rev. B6031View full textAdd to dashboardCite

“…In an ODCR measurement, cyclotron resonance ͑CR͒ is detected by observing changes in photoluminescence ͑PL͒ caused by cyclotron heating or cyclotroninduced impact ionization of bound carriers. [16][17][18] Thus CR detection can employ the advantages of using highly sensitive optical detectors, and it can be studied in a thin epitaxial layer. In our measurements, the PL signals were performed using an Ar ion laser.…”