(a) Sketch of the layer sequence of the strained InAs QW embedded in InGaAs. The 7 nm Mn modulation-doped layer is separated from the QW by a 5 nm spacer. (b) Schematic side view of the MCM (dark). The InAs QW sample (light) is thinned down to and attached to the flexible cantilever beam (dark). The MCM is mounted on a rotator stage allowing for in situ variation in the angle between the sample stage normal and . A torque acting on an anisotropic magnetic moment deflects the flexible cantilever beam and results in a capacitance change . (c) Sketch: Bird’s eye view of an MCM glued to a sapphire substrate hosting the Cr/Au counter electrode and guard ring.
(a) Oscillatory part of magnetization measured at and . Data were taken under illumination. (b) Magnetotransport measurement performed at in a separate cool-down at for an unilluminated sample.
Hysteretic behavior of around at 400 mK. The data were taken after illumination at . Arrows indicate the direction of the magnetic field sweep. The smoothed curves (solid lines) are a guide to the eyes. For below 0.05 T the noise level increased strongly due to a vanishing torque . We do not display data in this field regime.
(a) Torque as a function of absolute magnetic field for different angles . Data taken at 400 mK after illumination. (b) Torque at a constant field . The data represent averaged values for and −14 T. The solid line indicates a dependence of the torque on the angle . This corresponds to an uniaxial anisotropy.
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