3 Search Results

We present a novel application of a qubit-coupled phonon detector to search for new physics, e.g., ultralight dark matter (DM) and high-frequency gravitational waves. The detector, motivated by recent advances in quantum acoustics, is composed of superconducting transmon qubits coupled to high-overtone bulk acoustic resonators (ℎ⁡BARs) and operates in the GHz−10 GHz frequency range. New physics can excite 𝒪⁡(10 μ⁢eV) phonons within the ℎ⁡BAR, which are then converted to qubit excitations via a transducer. We detail the design, operation, backgrounds, and expected sensitivity of a prototype detector, as well as a next-generation detector optimized for new physics signals. We findmore » that a future detector can complement current haloscope experiments in the search for both dark photon DM and high-frequency gravitational waves. Lastly, we comment on such a detector’s ability to operate as a 𝒪⁡(10 μ⁢eV) athermal phonon sensor for sub-GeV DM detection.« less

Understanding phonon and charge propagation in superconducting devices plays an important role in both performing low-threshold dark matter searches and limiting correlated errors in superconducting qubits. The Geant4 Condensed Matter Physics (G4CMP) package, originally developed for the Cryogenic Dark Matter Search (CDMS) experiment, models charge and phonon transport within silicon and germanium detectors and has been validated by experimental measurements of phonon caustics, mean charge-carrier drift velocities, and heat pulse propagation times. Here, in this work, we present a concise framework for expanding the capabilities for phonon transport to a number of other novel substrate materials of interest to themore » dark matter and quantum computing communities, including sapphire (Al₂O₃), gallium arsenide (GaAs), lithium fluoride (LiF), calcium tungstate (CaWO₄), and calcium fluoride (CaF₂). We demonstrate the use of this framework in generating phonon transport properties of these materials and compare these properties with experimentally-determined values where available.« less

We present the first measurement of the negative pion total hadronic cross section on argon in a restricted phase space, which we performed at the Liquid Argon In A Testbeam (LArIAT) experiment. All hadronic reaction channels, as well as hadronic elastic interactions with scattering angle greater than 5° are included. The pions have kinetic energies in the range 100–700 MeV and are produced by a beam of charged particles impinging on a solid target at the Fermilab test beam facility. LArIAT employs a 0.24 ton active mass liquid argon time projection chamber (LArTPC) to measure the pion hadronic interactions. For this measurement,more » LArIAT has developed the “thin slice method,” a new technique to measure cross sections with LArTPCs. While moderately higher, our measurement of the ${\pi }^{-}$ -Ar total hadronic cross section is generally in agreement with the geant4 prediction.« less