A method for directional detection of dark matter using spectroscopy of crystal defects

Abstract

We propose a method to identify the direction of an incident Weakly Interacting Massive Particle (WIMP) via induced nuclear recoil. Our method is based on spectroscopic interrogation of quantum defects in macroscopic solid-state crystals . When a WIMP scatters in a crystal, the induced nuclear recoil creates a tell-tale damage cluster, localized to within about 50 nm, with an orientation to the damage trail that correlates well with the direction of the recoil and hence the incoming WIMP. This damage cluster induces strain in the crystal, shifting the energy levels of nearby quantum defects. These level shifts can be measured optically (or through paramagnetic resonance) making it possible to detect the strain environment around the defect in a solid sample. As a specific example, we consider nitrogen vacancy centers in diamond, for which high defect densities and nanoscale localization of individual defects have been demonstrated. To localize the millimeterscale region of a nuclear recoil within the crystal due to a potential dark matter event, we can use conventional WIMP detection techniques such as the collection of ionization/scintillation. Once an event is identified, the quantum defects in the vicinity of the event can be interrogated to map the strain environment, thus determining the direction of the recoil. In principle, this approach should be able to identify the recoil direction with an efficiency greater than 70 % at a false positive rate less than 5% for 10 keV recoil energies. If successful, this method would allow for directional detection of WIMP-induced nuclear recoils at solid state densities, enabling probes of WIMP parameter space below the solar neutrino floor. This technique could also potentially be applied to identify the direction of particles such as neutrons whose low scattering cross-section requires detectors with a large target mass.

Imaging crystal stress in diamond using ensembles of nitrogen-vacancy centers

“…diffraction limit [36,37]. Looking to future diamond applications for particle physics, diamond stress characterization is important for the recently-proposed diamond directional weaklyinteracting massive particle (WIMP) detector [15]. This approach aims to use NV centers to image the stress created by ∼100 nm tracks from recoiling carbon nuclei.…”

“…The stress tensor reconstruction can help identify how strain features formed during diamond sample preparation and thereby inform future sample fabrication. Finally, high-resolution NV stress imaging is essential in ongoing efforts to identify damage tracks from recoiling carbon nuclei to search for high-energy particle collisions in diamond [15]. In the following sections, we describe NV stress imaging and compare NV-based and birefringence images acquired with the same optical microscope.…”

Diamond detectors for direct detection of sub-GeV dark matter

“…In this time, the field of diamond electronics has become much more mature [25,29], and as industry has begun to produce lower-cost synthetic diamond substrates, these devices have come into broader use in particle physics, most recently as upgrades to both the ATLAS and CMS detectors [30]. Lattice vacancies in diamond have also become interesting to the quantum sensing community as potential qubit storage media, which may allow the use of diamond as a directional dark matter detector when used in conjunction with conventional technologies [31].…”

Multi-channel direct detection of light dark matter: theoretical framework

“…2 See also Refs. [38][39][40] for proposals that take advantage of direction-dependent threshold effects.…”