W07.00010. Interfacial Effects on Phonon Transport in Quantum Sensors for Dark Matter Detection
Presented by: Thomas Harrelson
Several proposals for the direct detection of dark matter (DM) of keV-MeV masses involve the scattering and absorption of DM with quasiparticles in the meV-eV energy transfer range. At these energy scales, phonons are the dominant energy carrier in most materials. Therefore, the task of detecting DM particles reduces to the detection of athermal distributions of phonons in a target material, which is accomplished using a transition edge sensor (TES). The phonons generated by DM scattering events in the target material propagate to the interface of the TES, and are either reflected or transmitted into the TES. We use density functional theory simulations to describe the probability at which phonon distributions are transmitted through the target/TES interface, and the coherence losses in quasiparticle transmission to the sensor. Specifically we calculate currently used targets Si and GaAs, with an Al TES. We consider the commercially available crystal faces for the target materials, and use these simulations to find the best target/TES interfaces for optimizing the phonon transmission coefficients. We use this information to create more accurate models of DM detection, which allows the optimization of the target material and interfaces in the quantum sensor.
- Thomas Harrelson
- Katherine Inzani
- Sinéad Griffin