A collaboration between the Equipe Théorie at MPQ and scientists from ETH Zurich and the Flatiron Institute has demonstrated, both theoretically and experimentally, that giant vacuum fields confined in a split-ring resonator cavity can profoundly alter electron-electron interactions in a quantum Hall system.
Two striking effects have been observed: a dramatic enhancement of fractional quantum Hall phases and a strong modification of spin splittings (g-factor renormalization). Both effects are explained by cavity-mediated long-range attractive interactions between electrons. The experimental setup uses a mobile, hovering cavity that allows in-situ tuning of the vacuum field strength above a GaAs-based two-dimensional electron gas.
Reference:
Tunable vacuum-field control of fractional and integer quantum Hall phases
Josefine Enkner, Lorenzo Graziotto, Dalin Boriçi, Felice Appugliese, Christian Reichl, Giacomo Scalari, Nicolas Regnault, Werner Wegscheider, Cristiano Ciuti & Jérôme Faist
Nature 641, 884–889 (2025)
Contact: Cristiano Ciuti
See also : ETH communication
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