Seeing Dark Matter in Multiferroics with Infrared and Raman Haloscopy

Several multiferroic materials have axion-like modes that resonate with terahertz frequency electromagnetic waves. Axions from the local dark matter halo of the galaxy allows such excitations to absorb mid-infrared light with wavelength near 2.44 microns and to Raman scatter visible light with wavenumber shift near 4100 inverse centimeters. Measuring the location of the peak in the infrared absorption and Raman scattering spectra with the resolution of readily available spectrometers would determine the mass of the axion with ten times better precision than the current world average for the mass of the charged particle that carries the weak nuclear force. Conversely, such infrared and Raman haloscopy gives a fast and easy way to find materials with axion-like excitations.