We propose two-dimensional materials as targets for direct detection of dark matter. Using graphene as an example, we focus on the case where dark matter scattering deposits sufficient energy on a valence-band electron to eject it from the target. We show that the sensitivity of graphene to dark matter of MeV to GeV mass can be comparable, for similar exposure and background levels, to that of semiconductor targets such as silicon and germanium. Moreover, a two-dimensional target is an excellent directional detector, as the ejected electron retains information about the angular dependence of the incident dark matter particle. This proposal can be implemented by the PTOLEMY experiment, presenting for the first time an opportunity for directional detection of sub-GeV dark matter.
|Original language||American English|
|Number of pages||8|
|Journal||Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics|
|State||Published - 10 Sep 2017|
Bibliographical noteFunding Information:
We thank Timothy Berkelbach, Garnet Chan, Youngkuk Kim, Andrew Rappe, and Joe Subotnik for enlightening discussions regarding graphene. We also thank Snir Gazit, Adolfo Grushin, Roni Ilan, Aaron Manalaysay, Dan McKinsey, Antonio Polosa, Matt Pyle, and Zohar Ringel for conversations about light dark matter detection in various materials. YH is supported by the U.S. National Science Foundation under Grant No. PHY-1002399 and Grant No. PHY-1419008, the LHC Theory Initiative. ML is supported by the DOE under contract DESC0007968, as well as by the Alfred P. Sloan Foundation. CT is supported by the Simons Foundation (#377485) and John Templeton Foundation (#58851). KZ is supported by the DOE under contract DE-AC02-05CH11231.
© 2017 The Author(s)
- Dark matter
- Direct detection
- Directional detection