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]
منابع مشابه
Direct measurement of the spin gaps in a gated GaAs two-dimensional electron gas
We have performed magnetotransport measurements on gated GaAs two-dimensional electron gases in which electrons are confined in a layer of the nanoscale. From the slopes of a pair of spin-split Landau levels (LLs) in the energy-magnetic field plane, we can perform direct measurements of the spin gap for different LLs. The measured g-factor g is greatly enhanced over its bulk value in GaAs (0.44...
متن کاملPossible Spin Polarization in a One-Dimensional Electron Gas.
In zero magnetic field, conductance measurements of clean one-dimensional (1D) constrictions defined in GaAs/AlGaAs heterostructures show twenty-six quantized ballistic plateaux, as well as a structure close to 0.7(2e 2 /h). In an in-plane magnetic field all the 1D subbands show Zeeman splitting and in the wide channel limit the g-factor is | g |= 0.4, close to that of bulk GaAs. For the last s...
متن کامل2 7 O ct 2 00 6 Charge and spin dynamics in a two dimensional electron gas
Abstract. A number of time resolved optical experiments probing and controlling the spin and charge dynamics of the high mobility two-dimensional electron gas in a GaAs/AlGaAs heterojunction are discussed. These include time resolved reflectivity, luminescence, transient grating, magneto-optical Kerr effect, and electro-optical Kerr effect experiments. The optical experiments provide informatio...
متن کاملTheory of spin-split cyclotron resonance in the extreme quantum limit.
We present an interpretation of recent cyclotron resonance experiments on the two-dimensional electron gas in GaAs/AlGaAs heterostructures. We show that the observed dependence of the resonance spectrum on Landau level occupancy and temperature arises from the interplay of three factors: spin-splitting of the cyclotron frequency; thermal population of the two spin states; and coupling of the re...
متن کاملCAPACITANCE OF A DOUBLE-HETEROJUNCTION GaAs/AlGaAs STRUCTURE SUBJECTED TO IN-PLANE MAGNETIC FIELDS: RESULTS OF SELF-CONSISTENT CALCULATIONS
The capacitance of a double-heterojunction structure with a wide GaAs undoped layer embedded between two selectively doped AlGaAs barriers is calculated self-consistently as a function of intensity of the in-plane magnetic field. With increasing field intensity the capacitance initially increases and after reaching a maximum decreases toward a high field limit which is less than its zero field ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 1997