It was a pleasure to welcome Prof. Ashwin Seshia from the University of Cambridge to the Cambridge Graphene Centre for a QAMSS Advanced Technology Lecture as part of the Michaelmas Term programme. Prof. Seshia delivered an engaging and insightful talk titled “Frequency Combs through Nonlinear Resonances in Micro/Nanomechanical Systems”, attracting a broad audience from across engineering, physics, and materials science.
In his lecture, Prof. Seshia introduced phononic frequency combs as distinctive mechanical response features characterised by evenly spaced spectral lines. He explained how these combs arise from nonlinear mode coupling and mixing in micro- and nanoelectromechanical systems, and how comb-like RF spectra can be generated using a single-tone drive. The talk traced the experimental development of phononic frequency combs, from early demonstrations in resonators with two coupled modes to more complex systems involving three coupled modes and capacitively transduced gyroscopic disk resonators.
Prof. Seshia highlighted how the observed comb structures are broadly consistent with theoretical models based on truncated Fermi–Pasta–Ulam–Tsingou (FPUT) chains. He also discussed the potential of engineered phononic frequency combs for practical applications, including stable resonance tracking in physical sensors, broadband vibration energy harvesting, and emerging component technologies for wireless communication and quantum information processing.
The QAMSS community greatly appreciated Prof. Seshia’s clear presentation and engaging discussion. This lecture forms part of the Michaelmas Term QAMSS SRI programme, which will conclude with an extra special QAMSS lecture next Monday, marking the close of the term.
