We propose a new broadband search strategy for ultralight axion dark matter that interacts with electromagnetism. An oscillating axion field induces transitions between two quasi-degenerate resonant modes of a superconducting cavity. In two broadband runs optimized for high and low masses, this setup can probe unexplored parameter space for axion-like particles covering fifteen orders of magnitude in mass, including astrophysically long-ranged fuzzy dark matter.
A Prototype Hybrid Mode Cavity for Heterodyne Axion Detection
SLAC National Accelerator Laboratory（SLAC国家加速器实验室）；Berkeley Center for Theoretical Physics, University of California, Berkeley（加州大学伯克利分校理论物理中心）；Theoretical Physics Group, Lawrence Berkeley National Laboratory（劳伦斯伯克利国家实验室理论物理组）；Theoretical Physics Division, Fermi National Accelerator Laboratory（费米国家加速器实验室理论物理部）；Superconducting Quantum Materials and Systems Center (SQMS), Fermi National Accelerator Laboratory（费米国家加速器实验室超导量子材料与系统中心（SQMS））；CERN（欧洲核子研究组织）；Departement de Physique Theorique, Universite de Geneve（日内瓦大学理论物理系）；Arizona State University（亚利桑那州立大学）
Sapienza Università di Roma（罗马大学）；INFN Sezione di Roma（意大利国家核物理研究所罗马分部）；Northeastern University（东北大学）；Quantum Materials and Sensing Institute, Northeastern University（东北大学量子材料与传感研究所）；Columbia University（哥伦比亚大学）
When ultralight axion dark matter encounters a static magnetic field, it sources an effective electric current that follows the magnetic field lines and oscillates at the axion Compton frequency. We propose a new experiment to detect this axion effective current. In the presence of axion dark matter, a large toroidal magnet will act like an oscillating current ring, whose induced magnetic flux can be measured by an external pickup loop inductively coupled to a SQUID magnetometer. We consider both resonant and broadband readout circuits and show that a broadband approach has advantages at small…
The mass of axion dark matter is only weakly bounded by cosmological observations, necessitating a variety of detection techniques over several orders of magnitude of mass ranges. Axions haloscopes based on resonant cavities have become the current standard to search for dark matter axions. Such structures are inherently narrowband and for low masses the volume of the required cavity becomes prohibitively large. Broadband low-mass detectors have already been proposed using inductive magnetometer sensors and a gapped toroidal solenoid magnet. In this work we propose an alternative, which uses e…
We introduce the Broadband Reflector Experiment for Axion Detection (BREAD) conceptual design and science program. This haloscope plans to search for bosonic dark matter across the [10$^{-3}$, 1] eV ([0.24, 240] THz) mass range. BREAD proposes a cylindrical metal barrel to convert dark matter into photons, which a novel parabolic reflector design focuses onto a photosensor. This unique geometry enables enclosure in standard cryostats and high-field solenoids, overcoming limitations of current dish antennas. A pilot 0.7 m$^{2}$ barrel experiment planned at Fermilab is projected to surpass exist…
Dark matter may consist of light, very weakly interacting bosons, produced non-thermally in the early Universe. Prominent examples of such very weakly interacting slim particles (WISPs) are axions and hidden photons. Direct detection experiments for such particles are based on the conversion of these particles into photons. This can be done in resonant cavities, featuring a resonant enhancement, or by using suitably shaped reflecting surfaces that allow for broadband searches. In this note we want to elucidate the relation between the two setups and study the transition from resonant to broadb…
A ferromagnetic haloscope is a rf spin-magnetometer used for searching Dark Matter in the form of axions. A magnetic material is monitored searching for anomalous magnetization oscillations which can be induced by dark matter axions. To properly devise such instrument one first needs to understand the features of the searched-for signal, namely the effective rf field of dark matter axions $B_a$ acting on electronic spins. Once the properties of $B_a$ are defined, the design and test of the apparatus may start. The optimal sample is a narrow linewidth and high spin-density material such as Yttr…
Light cold dark matter consisting of weakly interacting slim (or sub-eV) particles (WISPs) has been in the focus of a large number of studies made over the past two decades. The QCD axion and axion-like particles with masses in the $0.1\,μ$eV--$100\,$meV are strong candidates for the dark matter particle, together with hidden photons with masses below $\lesssim 100\,$meV. This motivates several new initiatives in the field, including the WISP Dark Matter eXperiment (WISPDMX) and novel conceptual approaches for broad-band WISP searches using radiometry measurements in large volume chambers. Fir…
The most sensitive haloscopes that search for axion dark matter through the two photon electromagnetic anomaly, convert axions into photons through the mixing of axions with a large DC magnetic field. In this work we apply Poynting theorem to the resulting axion modified electrodynamics and identify two possible Poynting vectors, one similar to the Abraham Poynting vector and the other to the Minkowski Poynting vector in electrodynamics. The latter picks up the extra non-conservative terms while the former does not. To understand the source of energy conversion and power flow in the detection …
The focus on dark matter search has expanded to include low-mass particles such as axions or axion-like particles, and novel theoretical schemes extending the phenomenological landscape, within QCD and beyond, also garnered additional interest in recent decades. Assuming dark matter is composed of axions, in presence of a solenoidal magnetic field, they induce a displacement current that gives rise to a toroidal magnetic field. The Weakly Interacting Slender Particle detection with LC circuit (WISPLC) is a precision direct detection experiment that will search for light dark matter candidates …
A brief review of light dark matter particles and their spectroscopy is presented, specifically aimed at understanding the interaction mechanisms of axion and Axion-Like Particles (ALPs) with matter and an interim proposal and some ideas for possible detection of these evasive particles. In order to venture into the highly challenging spectral regions and extremely weak signals involved with these searches (especially for the DFSZ axions), a different scheme is proposed departing from the conventional resonant cavity mass scan and heterodyne detection methods. We aim to look for a fixed mass a…
Two of the most pressing questions in physics are the microscopic nature of the dark matter that comprises 84% of the mass in the universe and the absence of a neutron electric dipole moment. These questions would be resolved by the existence of a hypothetical particle known as the quantum chromodynamics (QCD) axion. In this work, we probe the hypothesis that axions constitute dark matter, using the ABRACADABRA-10cm experiment in a broadband configuration, with world-leading sensitivity. We find no significant evidence for axions, and we present 95% upper limits on the axion-photon coupling do…
We study the new mechanism of the axion production suggested recently in [1,2]. This mechanism is based on the so-called Axion Quark Nugget (AQN) dark matter model, which was originally invented to explain the similarity of the dark and visible cosmological matter densities. We perform numerical simulations to evaluate the axion flux on the Earth's surface. We examine annual and daily modulations, which have been studied previously and are known to occur for any type of dark matter. We also discuss a novel type of short time enhancements which are unique to the AQN model: the statistical fluct…
We advocate an idea that the presence of the daily and annual modulations of the axion flux on the Earth surface may dramatically change the strategy of the axion searches. Our computations are based on the so-called Axion Quark Nugget (AQN) dark matter model which was originally put forward to explain the similarity of the dark and visible cosmological matter densities $Ω_{\rm dark}\sim Ω_{\rm visible}$. In our framework, the population of galactic axions with mass $ 10^{-6} {\rm eV}\lesssim m_a\lesssim 10^{-3}{\rm eV}$ and velocity $< v_a>\sim 10^{-3} c$ will be always accompanied by the axi…
We have proposed a model of a progenitor of fast radio bursts (FRBs): The FRBs are emitted by electrons in atmospheres of neutron stars when neutron stars collide with dark matter axion stars. We reexamine the model by taking account of the tidal forces of the neutron stars. The axion stars are distorted by the forces so that they become like long sticks when they are close to the neutron stars. Although the tidal forces fairly distort the axion stars, our model is still consistent with present observations. We explain a distinctive feature of our model that the FRBs are not broadband, but nar…
Axions and axion-like particles may couple to nuclear spins like a weak oscillating effective magnetic field, the "axion wind." Existing proposals for detecting the axion wind sourced by dark matter exploit analogies to nuclear magnetic resonance (NMR) and aim to detect the small transverse field generated when the axion wind resonantly tips the precessing spins in a polarized sample of material. We describe a new proposal using the homogeneous precession domain (HPD) of superfluid helium-3 as the detection medium, where the effect of the axion wind is a small shift in the precession frequency…
Dark Matter Search with a Resonantly-Coupled Hybrid Spin System
Beihang University（北京航空航天大学）；Hangzhou Extremely Weak Magnetic Field Major Science and Technology Infrastructure Research Institute（杭州极弱磁场重大科技基础设施研究院）；Hefei National Laboratory（合肥国家实验室）；Nanyang Technological University（南洋理工大学）；Peking University（北京大学）
Kavli Institute for the Physics and Mathematics of the Universe (WPI), University of Tokyo（东京大学 Kavli宇宙物理与数学研究所）；Institutes for Advanced Study, University of Tokyo（东京大学高等研究院）；Department of Applied Physics, The University of Tokyo（东京大学应用物理系）；Department of Physics, The University of Tokyo（东京大学物理系）
Axion search with telescope for radio astronomy (ASTRA): forecast for observations between 0.5 and 4~GHz
King’s College London（伦敦国王学院）；University of Virginia（弗吉尼亚大学）；University of California Berkeley（加州大学伯克利分校）；Instituto de Física de Cantabria (IFCA, UC-CSIC)（坎塔布里亚物理研究所）；The University of Sydney（悉尼大学）；The University of New South Wales（新南威尔士大学）；University of Washington（华盛顿大学）；Università degli Studi di Salerno（萨莱诺大学）；Istituto Nazionale di Fisica Nucleare - Gruppo Collegato di Salerno - Sezione di Napoli（意大利国家核物理研究所-萨莱诺协作组-那不勒斯分部）
Direct-detection searches for axions and hidden photons are playing an increasingly prominent role in the search for dark matter. In this work, we derive the properties of optimal electromagnetic searches for these candidates, subject to the Standard Quantum Limit (SQL) on amplification. We show that a single-pole resonant search may possess substantial sensitivity outside of the resonator bandwidth and that optimizing this sensitivity may increase scan rates by up to five orders of magnitude at low frequencies. Additional enhancements can be obtained with resonator quality factors exceeding o…
We review a testable, the axion quark nugget (AQN) model outside of the standard WIMP paradigm. The model was originally invented to explain the observed similarity between the dark and the visible components, $Ω_{\rm DM}\approx Ω_{\rm visible}$ in a natural way as both types of matter are formed during the same QCD transition and proportional to the same dimensional fundamental parameter of the system, $Λ_{\rm QCD}$. In this framework the baryogenesis is actually a charge segregation (rather than charge generation) process which is operational due to the $\cal{CP}$-odd axion field,while the g…
The cold dark matter of the Universe may be comprised of very light and very weakly interacting particles, so-called WISPs. Two prominent examples are hidden photons and axion-like particles. In this note we propose a new technique to sensitively search for this type of dark matter with dish antennas. The technique is broadband and allows to explore a whole range of masses in a single measurement.
Dark Matter Haloscope with a Disordered Dielectric Absorber
Research Laboratory of Electronics, Massachusetts Institute of Technology（麻省理工学院电子研究实验室）；Perimeter Institute for Theoretical Physics（理论物理前沿研究所）；Department of Physics and Astronomy, York University（约克大学物理与天文学系）；Department of Physics, University of Washington（华盛顿大学物理系）
For the first time, we determine the properties of the optimal single-moded, linear, passive search for electromagnetic coupling to axion and hidden-photon dark matter, subject to the Standard Quantum Limit on phase-insensitive amplification. We establish the parameters that must be considered to determine the optimal search: the impedance match to dark matter; receiver frequency-response and tuning; irreducible noise sources; and prior information on the dark-matter signal. Using complex-power flow equations, we identify two categories of coupling to the dark-matter signal: radiative and reac…
