| 摘要 |
<p>A microwave sweep oscillator or other signal source is used to apply a time varying signal to a scanning tunneling microscope and the current or voltage passing through a sample between the electrodes or the signal coupled by an electrode and reflected from the sample is measured by a microwave spectrum/network analyzer. The frequency of the signal applied by the oscillator may be swept across a spectrum and the optimum frequency of the spectrum is determined so that an improved image of the surface of a sample may be obtained. The spectrum of a known substance may also be recorded and used as a signature for identifying components of an unknown substance by comparison. When applied to electrochemical cells, dynamic information of the electrochemical cell can be measured. When applied to a Coulomb blockade device, charging thresholds and charge dissipation rates can be measured. Using multiple input frequencies, multiple substances may be monitored simultaneously. When applied to an array of Coulomb blockade devices used as a current standard, accuracy of the standard can be tested and the signal-to-noise ratio can be improved in the measurements, or the threshold of the devices can be detected.</p> |
