Wire metamaterial use for dark matter detection

Abstract

In this work we present our insights into the electromagnetic properties of a resonator recently suggested for the search of axions - a hypothetical candidate to particles of dark matter. A wire medium loaded resonator called a plasma haloscope when used to search for dark matter consists of a metal box filled with a dense array of parallel wires electrically connected to top and bottom walls. We show that the resonator quality <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$Q$</tex> at the frequency of our interest drops versus the growth of the resonator volume <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$V$</tex> until it is dominated by resistive losses in the wires. However, we find that in spite of these losses even at room temperature the metal like copper offer the quality factors in the thousands, an order of magnitude higher than the quality originally assumed by the authors of the concept. We have also found a way to tune the resonant frequency so that to better match the phases of the resonator eigenmode to that of the axion. It is achieved by mechanical movement of wires in relation to each other that allows up to 30% change in the resonance frequency. Finally, we discuss how to further improve the wire medium resonators for detection of axions.