Similar to a guitar string, the frequencies and lifetime of the nanomechanical resonators are similar. The quality factor is the number of times that the resonator changes shape until it reduces its energy by 70%. The quality factor is important for the modern applications of mechanical resonators as it determines the level of thermal noise, which is a limit for observing quantum effects.
The scientists at EPFL have shown that a regular polygon suspended at its edge supports high quality factors. The elastic properties of structures under tension are a result of the geometric symmetry of regular polygons. The approach to loss-engineering has an advantage over previous techniques in that it is able to realize high quality factors in smaller devices.
The new perimeter modes beat the record for the highest quality factor, but are almost 20 times more compact than devices with similar performance. In our laboratory, we try to measure and control mechanical vibrations at the quantum level using light, which requires suspension of mechanical resonators less than one micrometer from a structure which guides light. It is much simpler with compact devices.
The simple design of the polygon resonators allows the authors to make a chain of connected polygon resonators. A chain of coupled oscillators can behave differently than a single one. The dynamics of this chain are studied by the authors.
It is an important application of nanomechanical resonators. The authors show that the position fluctuations of a polygon resonator can be measured using an optical interferometer. This level of sensitivity approaches state-of-the-art atomic force microscopes.
Mohammad Bereyhi, who led the study published in Physical Review X, hopes that the demonstrated force sensitivity of the polygons combined with their compactness and simplicity will inspire their use in actual force microscopes.
State-of-the-art devices are very difficult to fabricate because of the cost of increased size and design complexity. It is a different story with perimeter modes. I believe that the simplicity of this new design greatly expands its potential to find new and promising applications.
More information: Mohammad J. Bereyhi et al, Perimeter Modes of Nanomechanical Resonators Exhibit Quality Factors Exceeding 109 at Room Temperature, Physical Review X (2022). DOI: 10.1103/PhysRevX.12.021036 Journal information: Physical Review X Citation: New nanomechanical oscillators with record-low loss (2022, May 12) retrieved 12 May 2022 from https://phys.org/news/2022-05-nanomechanical-oscillators-record-low-loss.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
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