Searching for axion dark matter with tuneable plasma haloscopes

by Dr Alexander Millar (Stockholm University and NORDITA)

Thursday 4 Apr 2019, 11:00 → 12:00 Europe/Berlin

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We propose a new strategy to search for dark matter axions using tuneable cryogenic plasmas. Unlike current experiments, which make up for discrepancy between the axion and photon masses via breaking translational invariance (cavity and dielectric haloscopes), a plasma haloscope matches the axion mass to the plasma frequency to resonantly enhance conversion. A key advantage is that the plasma frequency is unrelated to the physical size of the device, allowing for much larger conversion volumes. We identify wire metamaterials as an ideal candidate plasma, as they can be tuned by controlling the inter-wire spacing. For realistic experimental sizes we expect a competitive signal strength in for axion masses 35--400 mueV.