Absorption of light dark matter in semiconductors

Journal Article · 01 January 2017 · Physical Review D

DOI: https://doi.org/10.1103/PhysRevD.95.023013 · OSTI ID:1430675

Hochberg, Yonit ^[1]; Lin, Tongyan ^[2]; Zurek, Kathryn M. ^[2]

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1. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States). Berkeley Center for Theoretical Physics
2. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States). Berkeley Center for Theoretical Physics

Semiconductors are by now well-established targets for direct detection of MeV to GeV dark matter via scattering off electrons. We show that semiconductor targets can also detect significantly lighter dark matter via an absorption process. When the dark matter mass is above the band gap of the semiconductor (around an eV), absorption proceeds by excitation of an electron into the conduction band. Below the band gap, multiphonon excitations enable absorption of dark matter in the 0.01 eV to eV mass range. Energetic dark matter particles emitted from the sun can also be probed for masses below an eV. We derive the reach for absorption of a relic kinetically mixed dark photon or pseudoscalar in germanium and silicon, and show that existing direct detection results already probe new parameter space. Finally, with only a moderate exposure, low-threshold semiconductor target experiments can exceed current astrophysical and terrestrial constraints on sub-keV bosonic dark matter.

• Research Organization: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• Grant/Contract Number: AC02-05CH11231; PHY-1002399; PHY-1316783
• OSTI ID: 1430675
• Alternate ID(s): OSTI ID: 1341931
• Journal Information: Physical Review D, Vol. 95, Issue 2; ISSN 2470-0010
• Publisher: American Physical Society (APS)Copyright Statement
• Country of Publication: United States
• Language: English