Research Topics
Microwave Impedance Microscopy (MIM)
Near-field microscopy measures the localized electromagnetic properties at a length scale much smaller than the wavelength. The GHz (microwave) frequencies are high enough to eliminate Ohmic contact to the sample for the imaging and low enough to avoid any inter-band transition. The figures below illustrate the basic principle of our cantilever-based MIM. The microwave is fed to the tip and the reflected signal is amplified and demodulated by a mixer to produce the imaginary (MIM-Im) and real (MIM-Re) parts of the tip-sample impedance, from which the local dielectric constant and conductivity at the 10~100nm scale can be calculated.
Schematic of the standard MIM configuration
