The future search for low-frequency axions and new physics with the FLASH resonant cavity experiment at Frascati National Laboratories

We present a proposal for a new experiment, the FINUDA magnet for Light Axion SearcH (FLASH), a large resonant-cavity haloscope in a high static magnetic field which is planned to probe new physics in the form of dark matter (DM) axions, scalar fields, chameleons, hidden photons, as well as high frequency gravitational waves (GWs). Concerning the QCD axion, FLASH will search for these particles as the DM in the mass range (0.49-1.49) ueV, thus filling the mass gap between the ranges covered by other planned searches. A dedicated Microstrip SQUID operating at ultra-cryogenic temperatures will amplify the signal. The frequency range accessible overlaps with the Very High Frequency (VHF) range of the radio wave spectrum and allows for a search in GWs in the frequency range (100-300) MHz. The experiment will make use of the cryogenic plant and magnet of the FINUDA experiment at INFN Frascati National Laboratories near Rome (Italy); the operations needed to restore the functionalities of the apparatus are currently underway. We present the setup of the experiment and the sensitivity forecasts for the detection of axions, scalar fields, chameleons, hidden photons, and GWs

Josephson Junctions as Single Microwave Photon Counters: Simulation and Characterization

Detection of light dark matter, such as axion-like particles, puts stringent requirements on the efficiency and dark-count rates of microwave-photon detectors. The possibility of operating a current-biased Josephson junction as a single-microwave photon-detector was investigated through numerical simulations, and through an initial characterization of two Al junctions fabricated by shadow mask evaporation, done in a dilution refrigerator by measuring escape currents at different temperatures, from 40 mK up to the Al transition temperature. The escape dynamics of the junctions were reproduced in the simulation, including the dissipative effects. Inhibition of thermal activation was observed, leaving the macroscopic quantum tunneling as the dominant effect well beyond the crossover temperature

Social and economic determinants of reproductive behavior before the fertility decline: the case of six italian communities during the nineteenth century

In recent decades, main demographic historical research assessed the importance of bio-demographic components in human reproduction, before the diffusion of birth control and contraceptive techniques. According to this dominant view, before fertility decline, marital fertility was mainly regulated by biological and physiological factors and socio-economic factors played only a limited and indirect role. In order to demonstrate the importance of non-biological components, the present study focuses on six pre-transitional communities situated in different geographic areas of Italy. The work aims to demonstrate how fertility levels could significantly be affected by social and economic factors even in natural fertility populations, before the diffusion of contraceptives. Micro-level data are collected from several historical sources, and discrete-time event history models are applied to female reproductive careers in order to estimate effects of socio-economic status, household structure, and price fluctuations on marital fertility, controlling for several bio-demographic factors. Despite clear differences in geographic localization and environment, marital reproductive behavior appeared to be significantly and constantly affected by socio-economic status, household composition, and price levels in all the investigated communities

Microwave Photon Emission in Superconducting Circuits

Quantum computing requires a novel approach to store data as quantum states, opposite to classical bits. One of the most promising candidates is entangled photons. In this manuscript, we show the photon emission in the range of microwave frequencies of three different types of superconducting circuits, a SQUID, a JPA, and a JTWPA, often used as low-noise parametric amplifiers. These devices can be operated as sources of entangled photons. We report the experimental protocol used to produce and measure microwave radiation from these circuits, as well as data simulations. The collected spectra are obtained by performing single-tone measurements with a direct rf pump on the devices; the output spectra at low powers (below −100 dBm) are well interpreted by the dynamical Casimir model, while at high powers (above −100 dBm) the system is well described by the Autler–Townes fluorescence of a three-level atom

Microwave Losses in a DC Magnetic Field in Superconducting Cavities for Axion Studies

The hypothetical axion particle is an excellent cold dark matter candidate. Models predict an axion mass of tens of μ eV (GHz frequency range). In principle, it is possible to convert galactic axions into a monochromatic microwave signal or to detect them with an electron-spin flip. In both cases, to measure the resulting vanishing signal ( P ≈ 10 −23 W), a high- Q cavity is needed, with Q ∼ 10 6 . Superconducting RF technology can satisfy the requirement of operation in moderate-to-high dc magnetic fields. In this paper, we present an experimental study of the behavior of superconducting cavities in the vortex state. This study has been realized using 14 GHz Cu–NbTi and Cu–NbTiN x film cavities. A new cavity geometry is presented. We measured the magnetic field dependence of the Q -factor and Δ f res / f res , where f res is the resonant frequency in the range Β = 0–6 T at 4.2 K. Also, Q versus temperature at fixed B in zero-field-cooling and field-cooling setups has been considered. A comparison was made with Cu and Nb cylindrical bulk cavities . The data for Q( B ) were analyzed in terms of the elastic and dissipative motion of flux lines, thus including flux flow and flux pinning. We discuss whether the field-induced quasiparticle contribution is relevant in our field and temperature range

Characterization of a Transmon Qubit in a 3D Cavity for Quantum Machine Learning and Photon Counting

In this paper, we report the use of a superconducting transmon qubit in a 3D cavity for quantum machine learning and photon counting applications. We first describe the realization and characterization of a transmon qubit coupled to a 3D resonator, providing a detailed description of the simulation framework and of the experimental measurement of important parameters, such as the dispersive shift and the qubit anharmonicity. We then report on a Quantum Machine Learning application implemented on a single-qubit device to fit the u-quark parton distribution function of the proton. In the final section of the manuscript, we present a new microwave photon detection scheme based on two qubits coupled to the same 3D resonator. This could in principle decrease the dark count rate, favoring applications like axion dark matter searches

Status of the SIMP project: Towards the Single Microwave Photon Detection

The low-mass frontier of Dark Matter, the measurement of the neutrino mass, the search for new light bosons in laboratory experiments, all require detectors sensitive to excitations of meV or smaller. Faint and rare signals, such as those produced by vacuum photoemission or by an Axion in a magnetic field, could be efficiently detected only by a new class of sensors. The Italian institute for nuclear physics (INFN) has financed the three-year SIMP project (2019-2021) in order to strengthen its skills and technologies in this field with the ultimate aim of developing a single microwave photon detector. This goal will be pursued by improving the sensitivity and the dark count rate of two types of photodetectors: Current Biased Josephson Junction and Transition Edge Senso

Status of the SIMP project: Towards the Single Microwave Photon Detection

The low-mass frontier of Dark Matter, the measurement of the neutrino mass, the search for new light bosons in laboratory experiments, all require detectors sensitive to excitations of meV or smaller. Faint and rare signals, such as those produced by vacuum photoemission or by an Axion in a magnetic field, could be efficiently detected only by a new class of sensors. The Italian institute for nuclear physics (INFN) has financed the three-year SIMP project (2019-2021) in order to strengthen its skills and technologies in this field with the ultimate aim of developing a single microwave photon detector. This goal will be pursued by improving the sensitivity and the dark count rate of two types of photodetectors: Current Biased Josephson Junction and Transition Edge Senso