An ESN-STM spectrometer for single spin detection

Abstract We have designed and built an ESN-STM spectrometer dedicated to single electron spin detection. Our spectrometer couples a home-made STM with a Real-Time Spectrum Analyzer. The head of the spectrometer allows routine imaging of molecules deposited on surfaces with high tunnelling current set point. In order to provide a maximal ESN-STM signal power transfer from the source (i.e. tunnelling junction) to the amplifier stage we have developed an impedance matching circuit between the tunnelling junction and impedance of RF signal amplifier. Our impedance matching circuit is based on application of a wide-spectrum amplifier equipped with FET transistor. In order to validate the usefulness of our ESN-STM spectrometer tests of sensitivity are presented. The main advantage of our spectrometer is the fact that it allows the collection of spin spectra from every single point of the topography image.