Berlin 2024 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
TT: Fachverband Tiefe Temperaturen
TT 53: Focus Session: Nanomechanical Systems for Classical and Quantum Sensing II (joint session HL/DY/TT/QI)
TT 53.3: Talk
Wednesday, March 20, 2024, 15:30–15:45, EW 202
Topological phononic waveguides with ultralow loss — •Ilia Chernobrovkin1, Xiang Xi1, Jan Kosâta2, Oded Zilberberg3, Anders Sørensen1, and Albert Schliesser1 — 1Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, 2100 Copenhagen, Denmark — 2Institute for Theoretical Physics, ETH Zürich, 8093 Zürich, Switzerland — 3Department of Physics, University of Konstanz, 78464 Konstanz, Germany
Topological insulators have long intrigued researchers in terms of fundamental physical properties as well as potential applications. The advantages of topological insulators have been extended to the realm of bosonic defects or waveguiding systems and overturned some of conventional views of photonic or phononic wave manipulation. However, the existing topological phononic waveguides still have large transportation loss, which limits its applications.
In our work, we combine the so-called soft-clamping technique - which can dramatically suppress mechanical losses - with non-trivial topology, designed to enable valley-locked propagation along a topological edge. Our systems are based on sub-100 nm thin, highly stressed membrane made of silicon nitride membranes. Our preliminary experimental results show a measured Q-factor above 1 million for whispering-galley megahertz-frequency elastic modes along a closed triangular path of length of ~10 mm, which corresponds to a classical coherent length of tens of meters. Our system can be considered promising for use in phononic circuits for coherent microwave signal processing or interconnection.
Keywords: topological insulators; phononic waveguides; microresonators; nanotechnology