We propose a new strategy to search for dark matter axions in the mass range of $40--400\text{ }\ensuremath{\mu}\mathrm{eV}$ by introducing dielectric haloscopes, which consist of dielectric disks placed in a magnetic field. The changing dielectric media cause discontinuities in the axion-induced electric field, leading to the generation of propagating electromagnetic waves to satisfy the continuity requirements at the interfaces. Large-area disks with adjustable distances boost the microwave signal (10--100 GHz) to an observable level and allow one to scan over a broad axion mass range. A sensitivity to QCD axion models is conceivable with 80 disks of $1\text{ }\text{ }{\mathrm{m}}^{2}$ area contained in a 10 T field.

Dielectric Haloscopes: A New Way to Detect Axion Dark Matter