UHF multi-frequency lockin amplifier for nanomagnetism lab-on-a-chip

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This proposal requests a newly available electronic instrument capable of measuring UHF ("ultrahigh frequency", in this case up to 600 MHz) electrical signals in a uniquely sensitive manner. The tool will allow us to learn much more than we know now about the properties of single, tiny magnetic objects such as the building blocks of most data storage systems, and many naturally occuring magnetic nanoparticles which convey information about their environment. Lockin amplification, invented six decades ago by Robert Dicke at Princeton, is one of the most powerful electronic instrumentation techniques in the experimental physicist's toolkit. The method enables remarkably sensitive detection of small signals of an oscillatory nature. In essence, the idea is to use a "reference" wave, known to be at exactly the same frequency as the signal, as a template for examining a data stream very selectively in search only of patterns matching the fingerprint of the reference. The incorporation of digital electronics into lockin amplifiers began to improve the functionality of these instruments about two decades ago. Very recently the rate of improvement has increased markedly, opening new areas of application for the lockin technique at frequencies more than a million times higher than originally accessible, decades ago. The latest instrument now operates in the range of some of the most informative properties of magnetic nanosystems, their magnetic resonances.