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arXiv · 2606.30051

Hall viscosity from metric-sensitive dichroic probes

Alberto Nardin·Bruno Mera·Anaïs Defossez·Baptiste Bermond·Tomoki Ozawa·Nathan Goldman
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Abstract

Hall viscosity characterizes the geometric response of a quantum Hall droplet to deformations of the underlying metric, yet it has remained difficult to measure directly. We propose a spectroscopic probe based on circular dichroism, using chiral metric-sensitive drives -- implemented as rotating quadrupolar ("saddle") perturbations -- that effectively modulate the metric and couple to the generators of area-preserving deformations. The resulting dichroic signal directly measures the Hall viscosity, while frequency-resolved spectroscopy disentangles it from other excitations. A local formulation further enables spatially resolved markers of Hall viscosity applicable to both continuum and lattice systems. Our results open a direct route to measuring Hall viscosity in quantum-engineered platforms such as cold atoms in optical lattices.

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Alberto Nardin, Bruno Mera, Anaïs Defossez, Baptiste Bermond, Tomoki Ozawa, Nathan Goldman. 2026-06-29. Hall viscosity from metric-sensitive dichroic probes. https://arxiv.org/abs/2606.30051

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