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D. Di Gioacchino

Publications and source records attributed to D. Di Gioacchino.

At least 19 recordsLinked to original sources

Coherent oscillations in weakly anharmonic NbSe2 qubit

The functionalization of quantum devices to increase their performance and extend their fields of application is an extremely active research area. One of the most promising approaches is to replace aluminum with more performant materials. Within this context, van der Waals (vdW) materials are ideal candidates since they would allow to embed their unique properties into qubits. However, the realization of qubits based on vdW materials other than graphene is yet to be achieved. In this work we present a weakly anharmonic NbSe2 qubit. Our device exhibits a relaxation time T1 = 6.5 +\- 0.4 us which is roughly 2 orders of magnitude larger of other vdW qubits in addition to robustness to photon noise up to 5-10 thermal photons. Our work serves as a demonstrator of the advantage of integration of vdW materials into quantum technologies as well as serving as the first step toward the application of quantum non demolition photon detection protocols in the challenging field of dark matter search.

quant-ph↗

Search for Axion dark matter with the QUAX-LNF tunable haloscope

We report the first experimental results obtained with the new haloscope of the QUAX experiment located at Laboratori Nazionali di Frascati of INFN (LNF). The haloscope is composed of a OFHC Cu resonant cavity cooled down to about 30 mK and immersed in a magnetic field of 8 T. The cavity frequency was varied in a 6 MHz range between 8.831496 and 8.83803 GHz. This corresponds to a previously unprobed mass range between 36.52413 and 36.5511 $μ$eV. We don't observe any excess in the power spectrum and set limits on the axion-photon coupling in this mass range down to $g_{aγγ} < 0.861 \times 10^{-13}$ GeV$^{-1}$ with the confidence level set at $90\%$.

physics.ins-det↗

Search for galactic axions with a traveling wave parametric amplifier

A traveling wave parametric amplifier has been integrated in the haloscope of the QUAX experiment. A search for dark matter axions has been performed with a high Q dielectric cavity immersed in a 8 T magnetic field and read by a detection chain having a system noise temperature of about 2.1 K at the frequency of 10.353 GHz. Scanning has been conducted by varying the cavity frequency using sapphire rods immersed into the cavity. At multiple operating frequencies, the sensitivity of the instrument was at the level of viable axion models.

hep-ex↗

Stepping closer to pulsed single microwave photon detectors for axions search

Axions detection requires the ultimate sensitivity down to the single photon limit. In the microwave region this corresponds to energies in the yJ range. This extreme sensitivity has to be combined with an extremely low dark count rate, since the probability of axions conversion into microwave photons is supposed to be very low. To face this complicated task, we followed two promising approaches that both rely on the use of superconducting devices based on the Josephson effect. The first one is to use a single Josephson junction (JJ) as a switching detector (i.e. exploiting the superconducting to normal state transition in presence of microwave photons). We designed a device composed of a coplanar waveguide terminated on a current biased Josephson junction. We tested its efficiency to pulsed (pulse duration 10 ns) microwave signals, since this configuration is closer to an actual axions search experiment. We show how our device is able to reach detection capability of the order of 10 photons with frequency 8 GHz. The second approach is based on an intrinsically quantum device formed by two resonators coupled only via a superconducting qubit network (SQN). This approach relies on quantum nondemolition measurements of the resonator photons. We show that injecting RF power into the resonator, the frequency position of the resonant drop in the transmission coefficient (S21) can be modulated up to 4 MHz. We anticipate that, once optimized, both the devices have the potential to reach single photon sensitivity.

quant-ph↗

Progress in the development of a KITWPA for the DARTWARS project

DARTWARS (Detector Array Readout with Traveling Wave AmplifieRS) is a three years project that aims to develop high-performing innovative Traveling Wave Parametric Amplifiers (TWPAs) for low temperature detectors and qubit readout (C-band). The practical development follows two different promising approaches, one based on the Josephson junctions (TWJPA) and the other one based on the kinetic inductance of a high-resistivity superconductor (KITWPA). This paper presents the advancements made by the DARTWARS collaboration to produce a first working prototype of a KITWPA.

quant-ph↗

Search for galactic axions with a high-Q dielectric cavity

A haloscope of the QUAX--$aγ$ experiment, composed of an high-Q resonant cavity immersed in a 8 T magnet and cooled to $\sim 4.5$~K is operated to search for galactic axion with mass $m_a\simeq42.8~μ\text{eV}$. The design of the cavity with hollow dielectric cylinders concentrically inserted in a OFHC Cu cavity, allowed us to maintain a loaded quality-factor Q $\sim 300000$ during the measurements in presence of magnetic field. Through the cavity tuning mechanism it was possible to modulate the resonance frequency of the haloscope in the region $10.35337-10.35345$~GHz and thus acquire different dataset at different resonance frequencies. Acquiring each dataset for about 50 minutes, combining them and correcting for the axion's signal estimation-efficiency we set a limit on the axion-photon coupling $g_{aγγ}< 0.731\times10^{-13}$ GeV$^{-1}$ with the confidence level set at $90\%$.

hep-ex↗

Ultra low noise readout with travelling wave parametric amplifiers: the DARTWARS project

The DARTWARS project has the goal of developing high-performing innovative travelling wave parametric amplifiers with high gain, large bandwidth, high saturation power, and nearly quantum-limited noise. The target frequency region for its applications is 5 - 10 GHz, with an expected noise temperature of about 600 mK. The development follows two different approaches, one based on Josephson junctions and one based on kinetic inductance of superconductors. This contribution mainly focuses on the Josephson travelling wave parametric amplifier, presenting its design, preliminary measurements and the test of homogeneity of arrays of Josephson junctions.

quant-ph↗

A high-Q microwave dielectric resonator for axion dark matter haloscopes

The frequency band 1-15 GHz provides exciting prospects for resonant axion haloscopes as indicated by cosmological and astrophysical arguments. Among the challenges currently addressed to reach the required sensitivity, the development of high quality factor cavities that tolerate multi-Tesla fields plays a central role. We report a 3D resonator based on a right circular copper cavity with hollow cylinders that confine higher order modes around the cylinder axis. Its effective volume at 10.3\,GHz is $3.4 \cdot 10^{-2}$ liters, and under an 8\,T-field we measured an internal quality factor of more than 9 millions. These parameters demonstrate the potential of this unique resonator to probe galactic dark matter axion at remarkable scan rates of 15\,MHz/day when the cavity is readout by a quantum-limited receiver.

physics.ins-det↗

Bimodal Approach for Noise Figures of Merit Evaluation in Quantum-Limited Josephson Traveling Wave Parametric Amplifiers

The advent of ultra-low noise microwave amplifiers revolutionized several research fields demanding quantum-limited technologies. Exploiting a theoretical bimodal description of a linear phase-preserving amplifier, in this contribution we analyze some of the intrinsic properties of a model architecture (i.e., an rf-SQUID based Josephson Traveling Wave Parametric Amplifier) in terms of amplification and noise generation for key case study input states (Fock and coherents). Furthermore, we present an analysis of the output signals generated by the parametric amplification mechanism when thermal noise fluctuations feed the device.

cond-mat.supr-con↗

Detector Array Readout with Traveling Wave Amplifiers

Noise at the quantum limit over a large bandwidth is a fundamental requirement for future applications operating at millikelvin temperatures, such as the neutrino mass measurement, the next-generation x-ray observatory, the CMB measurement, the dark matter and axion detection, and the rapid high-fidelity readout of superconducting qubits. The read out sensitivity of arrays of microcalorimeter detectors, resonant axion-detectors, and qubits, is currently limited by the noise temperature and bandwidth of the cryogenic amplifiers. The DARTWARS (Detector Array Readout with Traveling Wave AmplifieRS) project has the goal of developing high-performing innovative traveling wave parametric amplifiers (TWPAs) with a high gain, a high saturation power, and a quantum-limited or nearly quantum-limited noise. The practical development follows two different promising approaches, one based on the Josephson junctions and the other one based on the kinetic inductance of a high-resistivity superconductor. In this contribution we present the aims of the project, the adopted design solutions and preliminary results from simulations and measurements.

cond-mat.supr-con↗

Search for invisible axion dark matter of mass m$_a=43~μ$eV with the QUAX--$aγ$ experiment

A haloscope of the QUAX--$aγ$ experiment composed of an oxygen-free high thermal conductivity-Cu cavity inside an 8.1 T magnet and cooled to $\sim200$ mK is put in operation for the search of galactic axion with mass $m_a\simeq43~μ\text{eV}$. The power emitted by the resonant cavity is amplified with a Josephson parametric amplifier whose noise fluctuations are at the standard quantum limit. With the data collected in about 1 h at the cavity frequency $ν_c=10.40176$ GHz, the experiment reaches the sensitivity necessary for the detection of galactic QCD-axion, setting the $90\%$ confidence level limit to the axion-photon coupling $g_{aγγ}<0.639\times10^{-13}$ GeV$^{-1}$.

hep-ex↗

Realization of a high quality factor resonator with hollow dielectric cylinders for axion searches

The realization and characterization of a high quality factor resonator composed of two hollow-dielectric cylinders with its pseudo-TM$_{030}$ mode resonating at 10.9 GHz frequency is discussed. The quality factor was measured at the temperatures 300 K and 4 K obtaining $\mbox{Q}_{300\mbox{K}}=(150,000\pm 2,000)$ and $\mbox{Q}_{4\mbox{K}}=(720,000\pm 10,000)$respectively, the latter corresponding to a gain of one order of magnitude with respect to a traditional copper cylindrical-cavity with the corresponding TM$_{010}$ mode resonating at the same frequency. The implications to dark-matter axion-searches with cavity experiments are discussed showing that the gain in quality factor is not spoiled by a reduced geometrical coupling $C_{030}$ of the cavity mode to the axion field. This reduction effect is estimated to be at most 20%. Numerical simulations show that frequency tuning of several hundreds MHz is feasible.

physics.ins-det↗

Tunable electronic structure and stoichiometry dependent disorder in Nanostructured VO$_x$ films

We present and discuss an original method to synthesize disordered Nanostructured (NS) VO$_x$ films with controlled stoichiometry and tunable electronic structures. In these NS films, the original lattice symmetry of the bulk vanadium oxides is broken and atoms are arranged in a highly disordered structure . The stoichiometry-dependent disorder as a function of the oxygen concentration has been characterized by in-situ X-ray Absorption Near-Edge Structure (XANES) spectroscopy identifying the spectroscopic fingerprints. Results show structural rearrangements that deviate from the octahedral symmetry with different coexisting disordered phases. The modulation of the electronic structure of the NS films based on the resulted stoichiometry and the quantum confinement in the NS particles are also discussed. We demonstrate the possibility to modulate the electronic structure of VO$_x$ NS films accessing new disordered atomic configurations with a controlled stoichiometry that provides an extraordinary opportunity to match a wide number of technological applications.

cond-mat.mes-hall↗

High quality factor photonic cavity for dark matter axion searches

Searches for dark matter axion involve the use of microwave resonant cavities operating in a strong magnetic field. Detector sensitivity is directly related to the cavity quality factor, which is limited, however, by the presence of the external magnetic field. In this paper we present a cavity of novel design whose quality factor is not affected by a magnetic field. It is based on a photonic structure by the use of sapphire rods. The quality factor at cryogenic temperature is in excess of $5 \times 10^5$ for a selected mode.

physics.ins-det↗

Axion search with a quantum-limited ferromagnetic haloscope

A ferromagnetic axion haloscope searches for Dark Matter in the form of axions by exploiting their interaction with electronic spins. It is composed of an axion-to-electromagnetic field transducer coupled to a sensitive rf detector. The former is a photon-magnon hybrid system, and the latter is based on a quantum-limited Josephson parametric amplifier. The hybrid system consists of ten 2.1 mm diameter YIG spheres coupled to a single microwave cavity mode by means of a static magnetic field. Our setup is the most sensitive rf spin-magnetometer ever realized. The minimum detectable field is $5.5\times10^{-19}\,$T with 9 h integration time, corresponding to a limit on the axion-electron coupling constant $g_{aee}\le1.7\times10^{-11}$ at 95% CL. The scientific run of our haloscope resulted in the best limit on DM-axions to electron coupling constant in a frequency span of about 120 MHz, corresponding to the axion mass range $42.4$-$43.1\,μ$eV. This is also the first apparatus to perform an axion mass scanning by changing the static magnetic field.

hep-ex↗

Tunable vortex dynamics in proximity junction arrays: a possible accurate and sensitive 2D THz detector

An array of superconducting proximity islands has been shown to be highly tunable by electric and magnetic fields. Indeed, a small change in the electric and magnetic field can tune the system from a vortex Mott insulator to a vortex metal. This transition from localized to a non-localized state can occur as soon as the density of the superconducting vortices matches the density of the pinning sites in a non defective structure. The possibility of further modulation of non-localized superconducting states via enhancement of the superconducting order parameter or modulation of the Josephson plasma frequency is discussed. Based on the non-bolometric effects associated with the occurrence of non-equilibrium phenomena in this original superconducting networks we discuss also the possible applications of this array for a conceptually new type of radiation detector.

cond-mat.supr-con↗

KLASH Conceptual Design Report

The last decade witnessed an increasing interest in axions and axion-like particles with many theoretical works published and many new experimental proposals that started a real race towards their discovery. This paper is the Conceptual Design Report of the KLASH (KLoe magnet for Axion SearcH) experiment at the Laboratori Nazionali di Frascati (LNF). The idea of this experiment has been stimulated by the availability of the large volume superconducting magnet, with a moderate magnetic field of 0.6 T, used in the KLOE detector at the DAFNE collider. The main conclusion we draw from this report is the possibility to build and put in operation at LNF in 2-3 years a large haloscope with the sensitivity to KSVZ axions in the low mass range between 0.2 and 1 $μ$eV, complementary to that of other experiments. Timeline and cost are competitive with respect to other proposals in the same mass region thanks to the availability of most of the infrastructure, in particular the superconducting magnet and the cryogenics plant.

physics.ins-det↗

Galactic axions search with a superconducting resonant cavity

To account for the dark matter content in our Universe, post-inflationary scenarios predict for the QCD axion a mass in the range $(10-10^3)\,μ\mbox{eV}$. Searches with haloscope experiments in this mass range require the monitoring of resonant cavity modes with frequency above 5\,GHz, where several experimental limitations occur due to linear amplifiers, small volumes, and low quality factors of Cu resonant cavities. In this paper we deal with the last issue, presenting the result of a search for galactic axions using a haloscope based on a $36\,\mbox{cm}^3$ NbTi superconducting cavity. The cavity worked at $T=4\,\mbox{K}$ in a 2\,T magnetic field and exhibited a quality factor $Q_0= 4.5\times10^5$ for the TM010 mode at 9\,GHz. With such values of $Q$ the axion signal is significantly increased with respect to copper cavity haloscopes. Operating this setup we set the limit $g_{aγγ}<1.03\times10^{-12}\,\mbox{GeV}^{-1}$ on the axion photon coupling for a mass of about 37\,$μ$eV. A comprehensive study of the NbTi cavity at different magnetic fields, temperatures, and frequencies is also presented.

physics.ins-det↗