Near-quantum-limited axion dark matter search with the ORGAN experiment around <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow> <mml:mrow> <mml:mn>26</mml:mn> <mml:mtext> </mml:mtext> <mml:mtext> </mml:mtext> <mml:mi mathvariant="normal">μ</mml:mi> <mml:mi>eV</mml:mi> </mml:mrow> </mml:mrow> </mml:math>
Aaron Quiskamp, Graeme Flower, Steven Samuels, Ben T. McAllister, P. A. Altin, E.N. Ivanov, Maxim Goryachev, Michael E. Tobar
Abstract
The latest result from the ORGAN experiment, an axion haloscope, is presented. This iteration of the experiment operated at millikelvin temperatures using a flux-driven Josephson parametric amplifier for reduced noise, along with various other improvements over previous iterations. Covering the <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"> <a:mrow> <a:mn>25.45</a:mn> <a:mo>−</a:mo> <a:mn>26.27</a:mn> <a:mtext> </a:mtext> <a:mtext> </a:mtext> <a:mi mathvariant="normal">μ</a:mi> <a:mi>eV</a:mi> </a:mrow> </a:math> (6.15–6.35 GHz) mass (frequency) range, this near-quantum-limited phase of ORGAN employs a conducting rod resonator and a 7-T solenoidal magnet to place the most sensitive exclusion limits on axion-photon coupling in the range to date, with <d:math xmlns:d="http://www.w3.org/1998/Math/MathML" display="inline"> <d:mo stretchy="false">|</d:mo> <d:msub> <d:mi>g</d:mi> <d:mrow> <d:mi>a</d:mi> <d:mi>γ</d:mi> <d:mi>γ</d:mi> </d:mrow> </d:msub> <d:mo stretchy="false">|</d:mo> <d:mo>≳</d:mo> <d:mn>2.8</d:mn> <d:mo>×</d:mo> <d:msup> <d:mn>10</d:mn> <d:mrow> <d:mo>−</d:mo> <d:mn>13</d:mn> </d:mrow> </d:msup> </d:math> at a 95% confidence level.