High-field exciton spectrum of gallium selenide

Abstract

The excitation spectrum of a free exciton in GaSe has been measured in magnetic fields up to nearly 200 T. The measured spectrum compares favorably with a theoretical calculation done within the effective-mass approximatio'n, consistent with a recent interpretation that the mass anisotropy is smail, p~~/p "=' 1.

Electronic structure of indium selenide probed by magnetoabsorption spectroscopy under high pressure

“…However, the magnetofingerprints are not really well understood, especially in the low-field region even if the large N transitions are quite consistent with linear LLs. 15,35,36 One can also notice on the contour map a feature similar with an avoided level crossing on the N = 1 level around 42 T ͑ϳ1.35 eV͒. In fact, as the energy difference between the linear LL N = 1 and the observed level crossing is equal to the longitudinal-optical ͑LO͒ phonon 26 meV which is known to give rise to an absorption peak at E Exc +LO ͑Ref.…”

Magneto-optical effects observed for GaSe in megagauss magnetic fields

“…Many papers have been published concerning magneto-optics of GaSe. [6][7][8][9][10] A dimensionless parameter ␥ϵ(បeB/2*)/R* is often used to represent the relative strength of the magnetic field in materials, where B is the magnetic field, * is the effective reduced mass of a electron and a hole, R* is the effective Rydberg energy, and បeB/2* corresponds to the zero-point energy of the Landau levels. As ␥ becomes unity at ϳ50 T in GaSe, the magnetic field much larger than 50 T is necessary to investigate the magneto-optics in the strong magnetic-field regime.…”

Magneto-excitons in Cu2O: theoretical model from weak to high magnetic fields

“…Note that for higher values of γ, the visibility of the hydrogen series will be smaller, since the corresponding oscillator strengths will decrease with increasing γ, and the distances between the maxima in satellite structures decrease. As pointed by Aldrich et al [29], for GaSe at γ=4 (B cr ∼50 T, B∼200 T), one observes the resonances at Landau energies, slightly red shifted for higher states, but the satellite structures were not observed. For Cu 2 O, even for the fields as high as B∼150 T [12], one does not observe satellite structures in the vicinity of Landau states, typical for the high magnetic field regime.…”