The authors demonstrate readout of electrically detected magnetic resonance at radio frequencies by means of a LCR tank circuit. Applied to a silicon field-effect transistor at millikelvin temperatures, this method shows a 25-fold increased signal-to-noise ratio of the conduction band electron spin resonance and a higher operational bandwidth of >300 kHz compared to the kilohertz bandwidth of conventional readout techniques. This increase in temporal resolution provides a method for future direct observations of spin dynamics in the electrical device characteristics.
View Article and Find Full Text PDFWe have embedded an AlGaAs/GaAs based, gated two-dimensional (2D) hole system (2DHS) into an impedance transformer LC circuit and show that by using radio-frequency reflectometry it is possible to perform sensitive, large bandwidth, electrical resistance measurements of 2D systems at millikelvin temperatures. We construct a simple lumped element model where the gated 2DHS is described as a resistive transmission line. The model gives a qualitative understanding of the experimental results.
View Article and Find Full Text PDFWe report a detailed study of low-temperature (mK) transport properties of a silicon double-dot system fabricated by phosphorous ion implantation. The device under study consists of two phosphorous nanoscale islands doped to above the metal-insulator transition, separated from each other and the source and drain reservoirs by nominally undoped (intrinsic) silicon tunnel barriers. Metallic control gates, together with an Al-AlO(x) single-electron transistor (SET), were positioned on the substrate surface, capacitively coupled to the buried dots.
View Article and Find Full Text PDFOccup Ther Health Care
August 2013
SUMMARY The purpose of this exploratory study was to describe the occupational goals and concerns of women who are homeless with children. Twenty-seven women with children living in homeless shelters completed interviews using the Canadian Occupational Performance Measure (COPM). Occupational issues and concerns were identified for each participant, and then they were pooled.
View Article and Find Full Text PDFWe report an unusual case of cardiac hamartoma involving the ventricular septum. The patient presented with palpitations and exertional chest pain. Echocardiography indicated a large homogeneous mass occupying the superior two-thirds of the ventricular septum.
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