Exceptionally high Verdet constant in gold nanodisc arrays

Gajendra Mulay; Shraddha Choudhary; Ashwin A Tulapurkar; Daria O Ignatyeva; Vladimir I Belotelov; Shriganesh S Prabhu; Venu Gopal Achanta

arXiv · 2512.04608

Exceptionally high Verdet constant in gold nanodisc arrays

Gajendra Mulay·Shraddha Choudhary·Ashwin A Tulapurkar·Daria O Ignatyeva·Vladimir I Belotelov·Shriganesh S Prabhu·Venu Gopal Achanta

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Abstract

Magneto-optical effects in non-magnetic noble metals can be greatly enhanced by leveraging the in-plane Lorentz force at engineered plasmonic resonances. We demonstrate a 2D array of gold nanodiscs designed to host a hybrid resonance of localized plasmon and surface lattice modes. The structure exhibits a Verdet constant of 1.98e6 deg/T.m, corresponding to a Faraday rotation of -0.15 deg at a 1 T magnetic field. This Verdet constant represents a 15-fold enhancement over unpatterned gold and is highly competitive with many plasmon-enhanced diamagnetic nanostructures. These findings offer new opportunities for harnessing strong magneto-plasmonic effects in optoelectronic devices by patterning common non-magnetic metals.

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Gajendra Mulay, Shraddha Choudhary, Ashwin A Tulapurkar, Daria O Ignatyeva, Vladimir I Belotelov, Shriganesh S Prabhu, Venu Gopal Achanta. 2025-12-04. Exceptionally high Verdet constant in gold nanodisc arrays. https://arxiv.org/abs/2512.04608

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