High-resolution imaging of gigahertz polarization response arising from the interference of reflected surface acoustic waves

Abstract

The surface polarization caused by traveling SAWs at 1.585 GHz has been imaged using a dynamic homodyne electrostatic force microscope technique. Instead of measuring topographic changes caused by the SAW, the reported technique measures polarization in the piezoelectric substrate arising from mechanical stress caused by the SAW. The polarization associated with this stress field modulates the scanning probe cantilever deflection amplitude, which is extracted using a lock-in-based technique. High-resolution imaging is presented with images of the interference arising from a metal reflector on a SAW device. A mathematical model combining SAW generation and force interactions between the probe and the substrate was used to verify the experimental data. In addition to overcoming the challenge associated with detecting and imaging polarization effects at gigahertz frequencies, this imaging technique will greatly assist the development of SAW-based devices that exploit the reflection and interference of SAWs in areas as diverse as microfluidic mixing, cell sorting, and quantum entanglement.

Quantum computing with quantum-Hall edge state interferometry

“…By using this exact model, we are able to assess the dynamic properties of the propagating WP and easily include electronelectron interaction or time-dependent potentials in the simulations. As an example, the exact inclusion of time-dependent potentials finds an important application in the numerical simulation of electron-transport sustained by surface acoustic waves (SAW) [90,91,92,93], which is another highly efficient on-demand protocol to control single-electrons transport in semiconductors [94].…”

Visualization of Surface-Acoustic-Wave Potential by Transmission-Mode Microwave Impedance Microscopy

“…Scanning laser interferometry, for example, images the out-of-plane displacement fields 12,13 with sub-picometer sensitivity and a diffraction-limited lateral resolution around 1 m. The spatial resolution of surface displacement fields can be improved to ~ 20 nm in scanning acoustic force microscopy (SAFM), which detects the nonlinear mixing of two slightly detuned SAWs through a cantilever probe at the difference frequency [14][15][16] . The sub-nm SAW amplitude has also been visualized by stroboscopic X-ray imaging 17,18 .…”