Applied Physics Letters · 1997 · 46 citations · 8 references
Natural SciencesElectrical EngineeringPhysicsCondensed Matter PhysicsElectromagnetismMagnetic MaterialsMagnetic Properties Of SolidsMagnetism In SolidsStrongly Correlated Electron SystemsSuperconducting Magnet SystemsSuperconducting MaterialsSuperconducting Thin FilmsCharge Carrier DensityLandau LevelsLow-frequency NoiseQuantum InterferenceSquid MagnetometersSuperconducting Quantum Interference Device MagnetometryTwo-dimensional Electron GasesTwo-dimensional Electron Systems
We report on new magnetization studies on a two-dimensional electron system (2DES) revealing spin splitting of the Landau levels. For this, we have built a high-sensitive susceptometer consisting of a low-noise thin-film dc superconducting quantum interference device (SQUID) with a multiturn input coil and a wire-wound first-order gradiometer. The system noise level is only 40×10−6 Φ0/√(Hz) down to a frequency of a few Hz in unshielded environment. In background fields up to 10 T, the system exhibits significant low-frequency noise. At frequencies above 1 kHz, however, the SQUID sensitivity is barely affected and we have reached a value of about 10−14 J/T at 1 T and better than 10−13 J/T at 10 T. With this, we have studied the de Haas–van Alphen effect for a tunable 2DES starting from zero carrier density.
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Specific Heat of Two-Dimensional Electrons in GaAs-GaAlAs Multilayers
E. Gornik, R. Lassnig, G. Strasser et al. · Physical Review Letters · 1985 · 257 citations