arXiv subjects

Maxim Goryachev

Publications and source records attributed to Maxim Goryachev.

At least 37 records · Page 2Linked to original sources

arXiv2024

Optomechanical dark matter instrument for direct detection

We propose the Optomechanical Dark-matter INstrument (ODIN), based on a new method for the direct detection of low-mass dark matter. We consider dark matter interacting with superfluid helium in an optomechanical cavity. Using an effective field theory, we calculate the rate at which dark matter scatters off phonons in a highly populated, driven acoustic mode of the cavity. This scattering process deposits a phonon into a second acoustic mode in its ground state. The deposited phonon ($μ$eV range) is then converted to a photon (eV range) via an optomechanical interaction with a pump laser. This photon can be efficiently detected, providing a means to sensitively probe keV scale dark matter. We provide realistic estimates of the backgrounds and discuss the technical challenges associated with such an experiment. We calculate projected limits on dark matter-nucleon interactions for dark matter masses ranging from 0.5 to 300 keV and estimate that a future device could probe cross-sections as low as $\mathcal{O}(10^{-32})$ cm$^2$.

hep-ph↗

arXiv2024

Scalar Gravitational Aharonov-Bohm Effect: Generalization of the Gravitational Redshift

The Aharonov-Bohm effect is a quantum mechanical phenomenon that demonstrates how potentials can have observable effects even when the classical fields associated with those potentials are absent. Initially proposed for electromagnetic interactions, this effect has been experimentally confirmed and extensively studied over the years. More recently, the effect has been observed in the context of gravitational interactions using atom interferometry. Additionally, recent predictions suggest that temporal variations in the phase of an electron wave function will induce modulation sidebands in the energy levels of an atomic clock, solely driven by a time-varying scalar gravitational potential [1]. In this study, we consider the atomic clock as a two-level system undergoing continuous Rabi oscillations between the electron's ground and excited state. We assume the photons driving the transition are precisely frequency-stabilized to match the transition, enabling accurate clock comparisons. Our analysis takes into account, that when an atom transitions from its ground state to an excited state, it absorbs energy, increasing its mass according to the mass-energy equivalence principle. Due to the mass difference between the two energy levels, we predict that an atomic clock in an eccentric orbit will exhibit a constant frequency shift relative to a ground clock corresponding to the orbit's average gravitational redshift, with additional modulation sidebands due to the time-varying gravitational potential.

quant-ph↗

arXiv2024

Microwave Cavity Mode Optimisation by Background Anti-Resonance Tuning

To derive the best oscillator phase noise when implementing a high-Q resonator, the spectral line-shape must have high contrast and symmetry. Ideally, this line-shape is Lorentzian, however, in a high mode density spectral region, low-Q background spurious modes interact and distort the resonance. For a sapphire-loaded cavity resonator operating with whispering gallery modes we show that this high contrast and symmetry can be achieved by changing the dimensions of the surrounding cavity shield to tune the background low-Q structures into anti-resonance. This works because the high-Q resonances are primarily defined by the sapphire while the background modes are defined by the cavity shield. Alternatively, it was shown that a similar result can be achieved by exciting the high-Q resonator with a balanced microwave dipole probe in a Mach Zehnder interferometric configuration. The probe was constructed from two separate coaxial electric field probes symmetrically inserted into a cylindrical cavity resonator, from opposite sides with a small gap between them, so they can behave like an active wire dipole antenna. The power into the two separate probes may be matched with an external variable attenuator in one of the arms of the interferometer. Conversely, the phase between the two electric field probes may be changed with an external variable phase shifter, which changes the nature of the field components the probe couples to. The probe couples to the high-Q resonant modes as well as low-Q background modes, which can be made resonant or anti-resonant for the high-Q modes by changing this external phase. When the background modes are in anti-resonance the line shape of the high-Q mode can be made symmetric and with higher contrast. This technique was applied to both whispering gallery sapphire modes, as well as hollow cavity resonators, without changing the dimensions of the cavity.

physics.app-ph↗

arXiv2024

Conductivity Freeze-Out in Isotopically Pure Si-28 at milli-Kelvin Temperatures

Silicon is a key semiconducting material for electrical devices and hybrid quantum systems where low temperatures and zero-spin isotopic purity can enhance quantum coherence. Electrical conductivity in Si is characterised by carrier freeze out at around 40 K allowing microwave transmission which is a key component for addressing spins efficiently in silicon quantum technologies. In this work, we report an additional sharp transition of the electrical conductivity in a Si-28 cylindrical cavity at around 1 Kelvin. This is observed by measuring microwave resonator Whispering Gallery Mode frequencies and Q factors with changing temperature and comparing these results with finite element models. We attribute this change to a transition from a relaxation mechanism-dominated to a resonant phonon-less absorption-dominated hopping conduction regime. Characterising this regime change represents a deeper understanding of a physical phenomenon in a material of high interest to the quantum technology and semiconductor device community and the impact of these results is discussed.

cond-mat.mtrl-sci↗

arXiv2024

Improved constraints on minimum length models with a macroscopic low loss phonon cavity

Many theories that attempt to formulate a quantum description of gravity suggest the existence of a fundamental minimum length scale. A popular method for incorporating this minimum length is through a modification of the Heisenberg uncertainty principle known as the generalised uncertainty principle (GUP). Experimental tests of the GUP applied to composite systems can be performed by searching for the induced frequency perturbations of the modes of mechanical resonators, thus constraining the degree of minimum length in certain scenarios. In this work previous constraints made with mechanical resonators are improved upon by three orders of magnitude, via the utilisation of a cryogenic quartz bulk acoustic wave resonator. As well as purely mechanical resonant modes; hybrid electromechanical anti-resonant modes are investigated, and shown to be sensitive to the same GUP induced effects.

gr-qc↗

arXiv2023

The Multi-mode Acoustic Gravitational Wave Experiment: MAGE

The Multi-mode Acoustic Gravitational wave Experiment (MAGE) is a high frequency gravitational wave detection experiment. In its first stage, the experiment features two near-identical quartz bulk acoustic wave resonators that act as strain antennas with spectral sensitivity as low as $6.6\times 10^{-21} \left[\textrm{strain}\right]/\sqrt{\textrm{Hz}}$ in multiple narrow bands across MHz frequencies. MAGE is the successor to the initial path-finding experiments; GEN 1 and GEN 2. These precursor runs demonstrated the successful use of the technology, employing a single quartz gravitational wave detector that found significantly strong and rare transient features. As the next step to this initial experiment, MAGE will employ further systematic rejection strategies by adding an additional quartz detector such that localised strains incident on just a single detector can be identified. The primary goals of MAGE will be to target signatures arising from objects and/or particles beyond that of the standard model, as well as identifying the source of the rare events seen in the predecessor experiment. The experimental set-up, current status and future directions for MAGE are discussed. Calibration procedures of the detector and signal amplification chain are presented. The sensitivity of MAGE to gravitational waves is estimated from knowledge of the quartz resonators. Finally, MAGE is assembled and tested in order to determine the thermal state of its new components.

gr-qc↗

arXiv2023

Gravitational Wave Detection with High Frequency Phonon Trapping Acoustic Cavities

There are a number of theoretical predictions for astrophysical and cosmological objects, which emit high frequency ($10^6-10^9$~Hz) Gravitation Waves (GW) or contribute somehow to the stochastic high frequency GW background. Here we propose a new sensitive detector in this frequency band, which is based on existing cryogenic ultra-high quality factor quartz Bulk Acoustic Wave cavity technology, coupled to near-quantum-limited SQUID amplifiers at $20$~mK. We show that spectral strain sensitivities reaching $10^{-22}$ per $\sqrt{\text{Hz}}$ per mode is possible, which in principle can cover the frequency range with multiple ($>100$) modes with quality factors varying between $10^6-10^{10}$ allowing wide bandwidth detection. Due to its compactness and well established manufacturing process, the system is easily scalable into arrays and distributed networks that can also impact the overall sensitivity and introduce coincidence analysis to ensure no false detections.

gr-qc↗

arXiv2023

Exclusion of ALP Cogenesis Dark Matter in a Mass Window Above 100 $μ$eV

We report the results of Phase 1b of The ORGAN Experiment, a microwave cavity haloscope searching for dark matter axions in the $107.42-111.93~μ$eV mass range. The search excludes axions with two-photon coupling $g_{aγγ}\geq 4\times 10^{-12}\, \textrm{GeV}^{-1}$ with $95\%$ confidence interval, setting the best upper bound to date and with the required sensitivity to exclude the axion-like particle cogenesis model for dark matter in this range. This result was achieved using a tunable rectangular cavity, which mitigated several practical issues that become apparent when conducting high mass axion searches, and was the first such axion search to be conducted with such a cavity. It also represents the most sensitive axion haloscope experiment to date in the $\sim100~μ$eV mass region.

hep-ex↗

arXiv2023

Searching for GUT-scale QCD Axions and Monopoles with a High Voltage Capacitor

The QCD axion has been postulated to exist because it solves the strong CP problem. Furthermore, if it exists axions should be created in the early Universe and could account for all the observed dark matter. In particular, axion masses of order $10^{-10}$ to $10^{-7}$ eV correspond to axions in the vicinity of the GUT-scale. In this mass range many experiments have been proposed to search for the axion through the standard QED coupling parameter $g_{aγγ}$. Recently axion electrodynamics has been expanded to include two more coupling parameters, $g_{aEM}$ and $g_{aMM}$, which could arise if heavy magnetic monopoles exist. In this work we show that both $g_{aMM}$ and $g_{aEM}$ may be searched for using a high voltage capacitor. Since the experiment is not sensitive to $g_{aγγ}$, it gives a new way to search for effects of heavy monopoles if the GUT-scale axion is shown to exist, or to simultaneously search for both the axion and the monopole at the same time.

hep-ph↗

arXiv2023

Searching for Low-Mass Axions using Resonant Upconversion

We present new results of a room temperature resonant AC haloscope, which searches for axions via photon upconversion. Traditional haloscopes require a strong applied DC magnetic background field surrounding the haloscope cavity resonator, the resonant frequency of which is limited by available bore dimensions. UPLOAD, the UPconversion Low-Noise Oscillator Axion Detection experiment, replaces this DC magnet with a second microwave background resonance within the detector cavity, which upconverts energy from the axion field into the readout mode, accessing axions around the beat frequency of the modes. Furthermore, unlike the DC case, the experiment is sensitive to a newly proposed quantum electromagnetodynamical axion coupling term $g_{aBB}$. Two experimental approaches are outlined - one using frequency metrology, and the other using power detection of a thermal readout mode. The results of the power detection experiment are presented, which allows exclusion of axions of masses between 1.12 $-$ 1.20 $μeV$ above a coupling strength of both $g_{aγγ}$ and $g_{aBB}$ at $3 \times 10^{-6}$ 1/GeV, after a measurement period of 30 days, which is a three order of magnitude improvement over our previous result.

hep-ex↗

arXiv2023

Sensitivity of Resonant Axion Haloscopes to Quantum Electromagnetodynamics

Recently interactions between putative axions and magnetic monopoles have been revisited by two of us [arXiv:2205.02605 [hep-ph]]. It has been shown that significant modifications to conventional axion electrodynamics arise due to these interactions, so that the axion-photon coupling parameter space is expanded from one parameter $g_{aγγ}$ to three $(g_{aγγ},g_{aAB},g_{aBB})$. We implement Poynting theorem to determine how to exhibit sensitivity to $g_{aAB}$ and $g_{aBB}$ using resonant haloscopes, allowing new techniques to search for axions and a possible indirect way to determine if magnetically charged matter exists.

hep-ph↗

arXiv2022

Limits on Dark Photons, Scalars, and Axion-Electromagnetodynamics with The ORGAN Experiment

Axions are a well-motivated dark matter candidate, with a host of experiments around the world searching for direct evidence of their existence. The ORGAN Experiment is a type of axion detector known as an axion haloscope, which takes the form of a cryogenic resonant cavity embedded in a strong magnetic field. ORGAN recently completed Phase 1a, a scan for axions around 65 \textmu eV, and placed the most stringent limits to date on the dark matter axion-photon coupling in this region, $|g_{aγγ}|\leq 3\times 10^{-12}$. It has been shown that axion haloscopes such as ORGAN are automatically sensitive to other kinds of dark matter candidates, such as dark photons, scalar field/dilaton dark matter, and exotic axion-electromagnetic couplings motivated by quantum electromagnetodynamics. We compute the exclusion limits placed on these various dark matter candidates by ORGAN 1a, and project sensitivity for some future ORGAN phases. In particular, the dark photon limits are the most sensitive to date in some regions of the parameter space.

hep-ph↗

arXiv2022

Probing the acoustic losses of graphene with a low-loss quartz bulk-acoustic-wave resonator at cryogenic temperatures

We observe mechanical effects of an exfoliated graphene monolayer deposited on a quartz crystal substrate designed to operate as an extremely low-loss bulk-acoustic-wave cavity at liquid-helium temperature.This is achieved by sensing overtones of the three thickness eigen-modes of the so-called SC-cut, since all three modes, two shear mode and one extensional mode, can be electrically probed with such a crystal cut. From quality-factor measurements, the mechanical losses of the adhesive graphene monolayer are assessed to be about 8 x 10-4 at 4 K in the best case. They are therefore significantly greater than those already reported for suspended membranes but also for adherent layers on SiO2/Si substrates operating in torsional modes. In fact, results reveal that surface scattering occurs due to a roughness degradation of a factor 7. In addition, the mechanical losses presented here are also placed in the context of a device submitted to thermomechanical stresses, but which are not the only ones existing. Some of them could be intrinsic ones related to the deposition process of the graphene layer. Based on a force-frequency theory applied to the three thickness modes which react differently to stresses, it is demonstrated that this stress effect actually entangled with that of mass loading reconciles the experimental results.

physics.app-ph↗

arXiv2022

Poynting vector controversy in axion modified electrodynamics

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 systems, we apply the two Poynting theorems to axion modified electrodynamics, for both the resonant cavity and broadband low-mass axion detectors. We show that both Poynting theorems give the same sensitivity for a resonant cavity axion haloscope, but predict markedly different sensitivity for a low-mass broadband capacitive haloscope. Hence we ask the question, can understanding which one is the correct one for axion dark matter detection, be considered under the framework of the Abraham-Minkowski controversy? In reality, this should be confirmed by experiment when the axion is detected. However, many electrodynamic experiments have ruled in favour of the Minkowski Poynting vector when considering the canonical momentum in dielectric media. In light of this, we show that the axion modified Minkowski Poynting vector should indeed be taken seriously for sensitivity calculation for low-mass axion haloscope detectors in the quasi static limit, and predict orders of magnitude better sensitivity than the Abraham Poynting vector equivalent.

hep-ph↗

arXiv2022

Electro-Mechanical Tuning of High-Q Bulk Acoustic Phonon Modes at Cryogenic Temperatures

We investigate the electromechanical properties of quartz bulk acoustic wave resonators at extreme cryogenic temperatures. By applying a DC bias voltage, we demonstrate broad frequency tuning of high-Q phonon modes in a quartz bulk acoustic wave cavity at cryogenic temperatures of 4 K and 20 mK. More than 100 line-widths of tuning of the resonance peak without any degradation in loaded quality factor, which are as high as $1.73\times 10^9$, is seen for high order overtone modes. For all modes and temperatures the observed coefficient of frequency tuning is $\approx$ 3.5 mHz/V per overtone number $n$ corresponding to a maximum of 255.5 mHz/V for the $n = 73$ overtone mode. No degradation in the quality factor is observed for any value of applied biasing field.

physics.app-ph↗

arXiv2022

Comparing Instrument Spectral Sensitivity of Dissimilar Electromagnetic Haloscopes to Axion Dark Matter and High Frequency Gravitational Waves

It is known that haloscopes that search for dark matter axions via the axion-photon anomaly are also sensitive to gravitational radiation through the inverse Gertsenshtein effect. Recently this way of searching for high frequency gravitational waves has gained momentum as it has been shown that the strain sensitivities of such detectors are of the same order of sensitivity to the axion-photon theta angle. Thus, after calculating the sensitivity of a haloscope to an axion signal, we also have calculated the order of magnitude sensitivity to a gravitational wave signal of the same spectral and temporal form. However, it is unlikely that a gravitational wave and an axion signal will be of the same form, since physically the way the signals are generated are completely different. For gravitational wave detection, the spectral strain sensitivity is in units strain per square root Hz, is the natural way to compare the sensitivity of gravitational wave detectors due to its independence on the gravitational wave signal. In this work, we introduce a systematic way to calculate the spectral sensitivity of an axion haloscope, so instrument comparison may be achieved independent of signal assumptions and only depends on the axion to signal transduction sensitivity and noise in the instrument. Thus, the calculation of the spectral sensitivity not only allows the comparison of dissimilar axion detectors independent of signal, but also allows us to compare the order of magnitude gravitational wave sensitivity in terms of spectral strain sensitivity, allowing comparisons to standard gravitational wave detectors based on optical interferometers and resonant-mass technology.

physics.ins-det↗

arXiv2022

Active Electric Dipole Energy Sources: Transduction via Electric Scalar and Vector Potentials

An active electrical network contains a voltage or current source that creates electromagnetic energy through a method of transduction that enables the separation of opposite polarity charges from an external source. The end result is the creation of an active dipole with a permanent polarisation and a non-zero electric vector curl. The external energy input impresses a force per unit charge within the voltage source, to form an active physical dipole in the static case, or an active Hertzian dipole in the time dependent case. This system is the dual of an electromagnet or permanent magnet excited by a circulating electrical current or fictitious bound current respectively, which supplies a magnetomotive force described by a magnetic vector potential with a magnetic geometric phase proportional to the enclosed magnetic flux. In contrast, the active electric dipole may be described macroscopically by a circulating fictitious magnetic current boundary source described by an electric vector potential with an electric geometric phase proportional to the enclosed electric flux density. This macroscopic description of an active dipole is an average description of some underlying microscopic description exhibiting emergent nonconservative behaviour not found in classical conservative laws of electrodynamics. We show that the electromotive force produced by an active dipole must have both electric scalar and vector potential components to account for the magnitude of the voltage it produces. Following this we analyse an active cylindrical dipole in terms of scalar and vector potential and confirm that the electromotive force produced, and hence potential difference across the terminals is a combination of vector and scalar potential difference depending on aspect ratio of the dipole.

physics.class-ph↗

arXiv2022

Direct Search for Dark Matter Axions Excluding ALP Cogenesis in the 63-67 micro-eV Range, with The ORGAN Experiment

The standard model axion seesaw Higgs portal inflation (SMASH) model is a well motivated, self-contained description of particle physics over a range of energy scales that predicts axion dark matter particles to exist within the mass range of $50-200\,μ$eV. To scan these masses an axion haloscope under a strong constant magnetic field must operate between 12 to 48 GHz. The ORGAN experiment (situated in Perth, Australia) is a microwave cavity axion haloscope that aims to search the majority of the mass range predicted by the SMASH model. Here we present results of Phase 1a, the first experiment to scan and search for axions in the microwave Ku Band. Our initial scan sets a new limit on the coupling of axions to two photons of $g_{aγγ}\geq 3\times 10^{-12}\, \textrm{GeV}^{-1}$ over the mass range $63.2$ to $67.1~μ$eV with $95\%$ confidence. This result is the most sensitive to date in this mass range, sufficient to exclude the well motivated ALP (Axion Like Particle) cogenesis model for dark matter, which adds ALPs to the standard model in the early universe to simultaneously explain the observed baryon and dark matter densities. To attain this level of sensitivity we utilised a TM$_{010}$ cylindrical cavity resonator, scanned between 15.28 to 16.23 GHz through the utilisation of a tuning rod. Measurements were performed over a duration of 3.5 weeks with a $74\%$ duty cycle, with the resonator coupled to a low noise HEMT amplifier and placed inside a superconducting solenoidal electromagnet of 11.5 Tesla in magnetic field strength.

hep-ex↗