Direct Measurements of the Spin Gap in the Two-Dimensional Electron Gas of AlGaAs-GaAs Heterojunctions
نویسندگان
چکیده
Using magnetocapacitance data, we directly determine the chemical potential jump at low temperatures of about 25 mK when the filling factor traverses the spin gap at n 1 and the cyclotron gap at n 2. The chemical potential jump for the cyclotron gap is found to increase proportionally to the magnetic field with a slope that is determined by an effective mass 0.071m0. The data yield a spin gap that also increases proportionally with magnetic field and is described by an enhanced Landé factor g ø 5.2. This result has not been explained by existing theoretical models. [S0031-9007(97)03709-5]
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