Ultrahigh-frequency silicon acousto-electronics

Research Topic

Acousto-electronic transport and phonon cavities generated by surface acoustic waves (SAWs) are playing a central role in the rapidly emerging field of quantum acoustics, a phonon analogue of quantum optics on a chip. To enter the quantum regime, both ultrahigh-frequency (UHF) (>10 GHz) SAWs and suitable host materials are indispensable. So far, research in this field has mainly concentrated on GaAs-based substrates. Silicon is attractive for its long spin lifetimes and thus, for the interconnectivity of qubits via SAWs generated by piezoelectric multilayers.


The overall objective of the project is to establish ultrahigh frequency acousto-transport in silicon via surface acoustic waves generated on piezoelectric multilayers by IDTs fabricated by nanoimprint lithography (NIL). The research will focus on high-frequency acousto-electronic transport in silicon using suitable piezoelectric multilayers. Investigation of available piezoelectric materials using both numerical simulations and validation through fabrication is now in progress. Acousto-electronic transport experiments will follow to investigate the characteristics of said multilayers and their suitability in application in as cavities or interconnects in quantum IT.


Robert Ukropec

Host: University of Twente – MESA+ Institute for Nanotechnology

Scientific Background

I achieved my Bachelor in Physics at the Comenius University in Bratislava, Slovakia. I continued my higher education at the RWTH University in Aachen, Germany, where I specialized in nanoelectronics. I completed my Master’s degree in Physics in the Semiconductor Nanoelectronics group at the Peter Grünberg Institute, Forschungszentrum Jülich, Germany. During my research, I successfully imaged contacted InAs nanowires using infrared near-field optical microscopy to gain insight into their surface conductance properties with manometer resolution.

Conference/Workshop Contributions
    • Ultrahigh-Frequency Silicon Acousto-Electronics
      R. Ukropec, B. Vratzov, P. V. Santos, W. G. van der Wiel
      SAWtrain Summer School: Physics and applications of GHz vibrations in semiconductors (Cargèse, France, July 11-21, 2017) | Internal
Conference/Workshop Contributions
    • High-frequency surface acoustic waves in silicon using nano- imprinting lithography
      R. Ukropec
      Spice workshop: Quantum Acoustics meet Surface Acoustic Waves meets Solid State Qubits (Mainz, Germany, May 17-20, 2016) | Internal