Showing papers by "Kaori Hattori published in 2014"
KEK1, Graduate University for Advanced Studies2, Lawrence Berkeley National Laboratory3, McGill University4, Japan Aerospace Exploration Agency5, University of California, Berkeley6, Tohoku University7, Okayama University8, University of Tokyo9, Osaka Prefecture University10, Max Planck Society11, Yokohama National University12, University of Tsukuba13, Saitama University14, Kindai University15
TL;DR: LiteBIRD as discussed by the authors is a next-generation satellite mission to measure the polarization of the cosmic microwave background (CMB) radiation, which carries the imprint of primordial gravitational waves.
Abstract: LiteBIRD is a next-generation satellite mission to measure the polarization of the cosmic microwave background (CMB) radiation. On large angular scales the B-mode polarization of the CMB carries the imprint of primordial gravitational waves, and its precise measurement would provide a powerful probe of the epoch of inflation. The goal of LiteBIRD is to achieve a measurement of the characterizing tensor to scalar ratio $$r$$
to an uncertainty of $$\delta r=0.001$$
. In order to achieve this goal we will employ a kilo-pixel superconducting detector array on a cryogenically cooled sub-Kelvin focal plane with an optical system at a temperature of 4 K. We are currently considering two detector array options; transition edge sensor (TES) bolometers and microwave kinetic inductance detectors. In this paper we give an overview of LiteBIRD and describe a TES-based polarimeter designed to achieve the target sensitivity of 2
$$\upmu $$
K arcmin over the frequency range 50–320 GHz.
455 citations
University of Chicago1, Cardiff University2, Stanford University3, University of California, San Diego4, University of Colorado Boulder5, McGill University6, Argonne National Laboratory7, University of California, Berkeley8, Canadian Institute for Advanced Research9, KEK10, National Institute of Standards and Technology11, University of California, Davis12, Lawrence Berkeley National Laboratory13, Massachusetts Institute of Technology14, California Institute of Technology15, University of Melbourne16, Case Western Reserve University17, Harvard University18, University of Toronto19, University of Illinois at Urbana–Champaign20
TL;DR: SPT-3G as discussed by the authors is a new polarization sensitive receiver for the 10-meter South Pole Telescope (SPT), which will enable the advance from statistical detection of B-mode polarization anisotropy power to high signal-to-noise measurements of individual modes, i.e., maps.
Abstract: We describe the design of a new polarization sensitive receiver, SPT-3G, for the 10-meter South Pole Telescope (SPT). The SPT-3G receiver will deliver a factor of ~20 improvement in mapping speed over the current receiver, SPT-POL. The sensitivity of the SPT-3G receiver will enable the advance from statistical detection of B-mode polarization anisotropy power to high signal-to-noise measurements of the individual modes, i.e., maps. This will lead to precise (~0.06 eV) constraints on the sum of neutrino masses with the potential to directly address the neutrino mass hierarchy. It will allow a separation of the lensing and inflationary B-mode power spectra, improving constraints on the amplitude and shape of the primordial signal, either through SPT-3G data alone or in combination with BICEP2/KECK, which is observing the same area of sky. The measurement of small-scale temperature anisotropy will provide new constraints on the epoch of reionization. Additional science from the SPT-3G survey will be significantly enhanced by the synergy with the ongoing optical Dark Energy Survey (DES), including: a 1% constraint on the bias of optical tracers of large-scale structure, a measurement of the differential Doppler signal from pairs of galaxy clusters that will test General Relativity on ~200Mpc scales, and improved cosmological constraints from the abundance of clusters of galaxies.
416 citations
TL;DR: In this article, a measurement of the B-mode polarization power spectrum in the cosmic microwave background (CMB) using the POLARBEAR experiment in Chile is reported, including both systematic and statistical uncertainties.
Abstract: We report a measurement of the B-mode polarization power spectrum in the cosmic microwave background (CMB) using the POLARBEAR experiment in Chile. The faint B-mode polarization signature carries information about the Universe's entire history of gravitational structure formation, and the cosmic inflation that may have occurred in the very early Universe. Our measurement covers the angular multipole range 500 < l < 2100 and is based on observations of an effective sky area of 25 square degrees with 3.5 arcmin resolution at 150 GHz. On these angular scales, gravitational lensing of the CMB by intervening structure in the Universe is expected to be the dominant source of B-mode polarization. Including both systematic and statistical uncertainties, the hypothesis of no B-mode polarization power from gravitational lensing is rejected at 97.1% confidence. The band powers are consistent with the standard cosmological model. Fitting a single lensing amplitude parameter A_BB to the measured band powers, A_BB = 1.12 +/- 0.61 (stat) +0.04/-0.12 (sys) +/- 0.07 (multi), where A_BB = 1 is the fiducial WMAP-9 LCDM value. In this expression, "stat" refers to the statistical uncertainty, "sys" to the systematic uncertainty associated with possible biases from the instrument and astrophysical foregrounds, and "multi" to the calibration uncertainties that have a multiplicative effect on the measured amplitude A_BB.
349 citations
TL;DR: SPT-3G as mentioned in this paper is a new polarization sensitive receiver for the 10-meter South Pole Telescope (SPT), which will enable the advance from statistical detection of B-mode polarization anisotropy power to high signal-to-noise measurements of the individual modes.
Abstract: We describe the design of a new polarization sensitive receiver, SPT-3G, for the 10-meter South Pole Telescope (SPT). The SPT-3G receiver will deliver a factor of ~20 improvement in mapping speed over the current receiver, SPTpol. The sensitivity of the SPT-3G receiver will enable the advance from statistical detection of B-mode polarization anisotropy power to high signal-to-noise measurements of the individual modes, i.e., maps. This will lead to precise (~0.06 eV) constraints on the sum of neutrino masses with the potential to directly address the neutrino mass hierarchy. It will allow a separation of the lensing and inflationary B-mode power spectra, improving constraints on the amplitude and shape of the primordial signal, either through SPT-3G data alone or in combination with BICEP-2/KECK, which is observing the same area of sky. The measurement of small-scale temperature anisotropy will provide new constraints on the epoch of reionization. Additional science from the SPT-3G survey will be significantly enhanced by the synergy with the ongoing optical Dark Energy Survey (DES), including: a 1% constraint on the bias of optical tracers of large-scale structure, a measurement of the differential Doppler signal from pairs of galaxy clusters that will test General Relativity on ~200 Mpc scales, and improved cosmological constraints from the abundance of clusters of galaxies.
339 citations
Graduate University for Advanced Studies1, University of Colorado Boulder2, University of California, San Diego3, University of California, Berkeley4, Lawrence Berkeley National Laboratory5, Dalhousie University6, KEK7, McGill University8, International School for Advanced Studies9, Paris Diderot University10, Columbia University11, Rutherford Appleton Laboratory12, Institute for the Physics and Mathematics of the Universe13, University of Oxford14, Austin College15, Imperial College London16, Princeton University17, University of Chicago18, University of Pennsylvania19, Goddard Space Flight Center20, Napa Valley College21, University of California, Irvine22, Tel Aviv University23, Osaka University24
TL;DR: In this paper, a measurement of the B-mode polarization power spectrum in the cosmic microwave background (CMB) using the POLARBEAR experiment in Chile is reported, which is based on observations of an effective sky area of 25? with 3.'5 resolution at 150?GHz.
Abstract: We report a measurement of the B-mode polarization power spectrum in the cosmic microwave background (CMB) using the POLARBEAR experiment in Chile. The faint B-mode polarization signature carries information about the universe's entire history of gravitational structure formation, and the cosmic inflation that may have occurred in the very early universe. Our measurement covers the angular multipole range 500 < ? < 2100 and is based on observations of an effective sky area of 25? with 3.'5 resolution at 150?GHz. On these angular scales, gravitational lensing of the CMB by intervening structure in the universe is expected to be the dominant source of B-mode polarization. Including both systematic and statistical uncertainties, the hypothesis of no B-mode polarization power from gravitational lensing is rejected at 97.2% confidence. The band powers are consistent with the standard cosmological model. Fitting a single lensing amplitude parameter ABB to the measured band powers, , where ABB = 1 is the fiducial WMAP-9 ?CDM value. In this expression, stat refers to the statistical uncertainty, sys to the systematic uncertainty associated with possible biases from the instrument and astrophysical foregrounds, and multi to the calibration uncertainties that have a multiplicative effect on the measured amplitude ABB .
283 citations
Cardiff University1, Graduate University for Advanced Studies2, University of Colorado Boulder3, University of California, San Diego4, Lawrence Berkeley National Laboratory5, Dalhousie University6, University of California, Berkeley7, McGill University8, Rutherford Appleton Laboratory9, KEK10, Institute for the Physics and Mathematics of the Universe11, Austin College12, Imperial College London13, Princeton University14, University of Chicago15, University of Tokyo16, Goddard Space Flight Center17, Osaka University18
TL;DR: The first direct evidence for polarization lensing based on purely CMB information is reported, from using the four-point correlations of even- and odd-parity E- and B-mode polarization mapped over ∼30 square degrees of the sky measured by the POLARBEAR experiment.
Abstract: Gravitational lensing due to the large-scale distribution of matter in the cosmos distorts the primordial cosmic microwave background (CMB) and thereby induces new, small-scale B-mode polarization. This signal carries detailed information about the distribution of all the gravitating matter between the observer and CMB last scattering surface. We report the first direct evidence for polarization lensing based on purely CMB information, from using the four-point correlations of even- and odd-parity E- and B-mode polarization mapped over ∼30 square degrees of the sky measured by the POLARBEAR experiment. These data were analyzed using a blind analysis framework and checked for spurious systematic contamination using null tests and simulations. Evidence for the signal of polarization lensing and lensing B modes is found at 4.2σ (stat+sys) significance. The amplitude of matter fluctuations is measured with a precision of 27%, and is found to be consistent with the Lambda cold dark matter cosmological model. This measurement demonstrates a new technique, capable of mapping all gravitating matter in the Universe, sensitive to the sum of neutrino masses, and essential for cleaning the lensing B-mode signal in searches for primordial gravitational waves.
199 citations
Cardiff University1, Graduate University for Advanced Studies2, University of Colorado Boulder3, University of California, San Diego4, Lawrence Berkeley National Laboratory5, California Institute of Technology6, Dalhousie University7, University of California, Berkeley8, McGill University9, International School for Advanced Studies10, Rutherford Appleton Laboratory11, KEK12, Institute for the Physics and Mathematics of the Universe13, Austin College14, Imperial College London15, Princeton University16, Paris Diderot University17, University of Chicago18, Goddard Space Flight Center19, Osaka University20
TL;DR: The gravitational lensing convergence signal from cosmic microwave background (CMB) polarization data taken by the Polarbear experiment is reconstructed and cross-correlate it with cosmic infrared background maps from the Herschel satellite to obtain evidence for gravitational lenser lensing of the CMB polarization.
Abstract: We reconstruct the gravitational lensing convergence signal from cosmic microwave background (CMB) polarization data taken by the Polarbear experiment and cross-correlate it with cosmic infrared background maps from the Herschel satellite. From the cross spectra, we obtain evidence for gravitational lensing of the CMB polarization at a statistical significance of 4.0σ and indication of the presence of a lensing B-mode signal at a significance of 2.3σ. We demonstrate that our results are not biased by instrumental and astrophysical systematic errors by performing null tests, checks with simulated and real data, and analytical calculations. This measurement of polarization lensing, made via the robust cross-correlation channel, not only reinforces POLARBEAR auto-correlation measurements, but also represents one of the early steps towards establishing CMB polarization lensing as a powerful new probe of cosmology and astrophysics.
119 citations
University of California, San Diego1, Cardiff University2, Graduate University for Advanced Studies3, University of Colorado Boulder4, McGill University5, University of California, Berkeley6, Lawrence Berkeley National Laboratory7, Dalhousie University8, KEK9, Paris Diderot University10, Institute for the Physics and Mathematics of the Universe11, Imperial College London12, University of Tokyo13, Princeton University14, University of Chicago15, Japan Aerospace Exploration Agency16, Goddard Space Flight Center17, University of Melbourne18, Osaka University19
TL;DR: The Simons Array is an extension of the POLARBEAR cosmic microwave background (CMB) polarization experiment currently observing from the Atacama Desert in Northern Chile.
Abstract: The Simons Array is an expansion of the POLARBEAR cosmic microwave background (CMB) polarization experiment currently observing from the Atacama Desert in Northern Chile. This expansion will create an array of three 3.5m telescopes each coupled to a multichroic bolometric receiver. The Simons Array will have the sensitivity to produce a ≥ 5σ detection of inationary gravitational waves with a tensor-to-scalar ratio r ≥ 0:01, detect the known minimum 58 meV sum of the neutrino masses with 3σ confidence when combined with a next-generation baryon acoustic oscillation measurement, and make a lensing map of large-scale structure over the 80% of the sky available from its Chilean site. These goals require high sensitivity and the ability to extract the CMB signal from contaminating astrophysical foregrounds; these requirements are met by coupling the three high-throughput telescopes to novel multichroic lenslet-coupled pixels each measuring CMB photons in both linear polarization states over multiple spectral bands. We present the status of this instrument already under construction, and an analysis of its capabilities.
44 citations
TL;DR: The POLARBEAR-2 experiment as mentioned in this paper is a cosmic microwave background polarimetry experiment, which aims to characterize the small angular scale B-mode signal due to gravitational lensing and search for the large angular scale signal from inflationary gravitational waves.
Abstract: We present an overview of the design and development of the POLARBEAR-2 experiment. The POLARBEAR-2 experiment is a cosmic microwave background polarimetry experiment, which aims to characterize the small angular scale B-mode signal due to gravitational lensing and search for the large angular scale B-mode signal from inflationary gravitational waves. The experiment will have a 365 mm diameter multi-chroic focal plane filled with 7,588 polarization sensitive antenna-coupled Transition Edge Sensor bolometers and will observe at 95 and 150 GHz. The focal plane is cooled to 250 mK. The bolometers will be read-out by SQUIDs with $$32\times $$
frequency domain multiplexing. The experiment will utilize high purity alumina lenses and thermal filters to achieve the required high optical throughput. A continuously rotating, cooled half-wave plate will be used to give stringent control over systematic errors. The experiment is designed to achieve a noise equivalent temperature of 5.7
$$\mu $$
K
$$\sqrt{s}$$
, and this allows us to constrain the signal from the inflationary primordial gravitational corresponding to a tensor-to-scalar ratio of $$r = 0.01$$
(
$$2\sigma $$
). POLARBEAR-2 will also be able to put a constraint on the sum of neutrino masses to 90 meV (
$$1\sigma $$
) with POLARBEAR-2 data alone and 65 meV (
$$1\sigma $$
) when combined with the Planck satellite. We plan to start observations in 2014 in the Atacama Desert in Chile.
28 citations
Japan Aerospace Exploration Agency1, Graduate University for Advanced Studies2, Lawrence Berkeley National Laboratory3, Tohoku University4, McGill University5, Canadian Institute for Advanced Research6, University of Tokyo7, University of California, Berkeley8, Osaka Prefecture University9, Okayama University10, Institute for the Physics and Mathematics of the Universe11, Max Planck Society12, Yokohama National University13, University of Tsukuba14, Saitama University15, Kyoto University16, Konan University17, Osaka University18, National Institute of Information and Communications Technology19
TL;DR: LBIRD as mentioned in this paper is a next generation satellite for the study of B-mode polarization and inflation from cosmic microwave background radiation (CMB) detection, and it can measure the CMB polarization with the sensitivity of δr = 0:001.
Abstract: We present the mission design of LiteBIRD, a next generation satellite for the study of B-mode polarization and inflation from cosmic microwave background radiation (CMB) detection. The science goal of LiteBIRD is to measure the CMB polarization with the sensitivity of δr = 0:001, and this allows testing the major single-field slow-roll inflation models experimentally. The LiteBIRD instrumental design is purely driven to achieve this goal. At the earlier stage of the mission design, several key instrumental specifications, e.g. observing band, optical system, scan strategy, and orbit, need to be defined in order to process the rest of the detailed design. We have gone through the feasibility studies for these items in order to understand the tradeoffs between the requirements from the science goal and the compatibilities with a satellite bus system. We describe the overview of LiteBIRD and discuss the tradeoffs among the choices of scientific instrumental specifications and strategies. The first round of feasibility studies will be completed by the end of year 2014 to be ready for the mission definition review and the target launch date is in early 2020s.
18 citations
University of California, San Diego1, Cardiff University2, Graduate University for Advanced Studies3, McGill University4, University of California, Berkeley5, Lawrence Berkeley National Laboratory6, Dalhousie University7, KEK8, International School for Advanced Studies9, Paris Diderot University10, University of Colorado Boulder11, Institute for the Physics and Mathematics of the Universe12, University of Tokyo13, Princeton University14, Japan Aerospace Exploration Agency15, Osaka University16
TL;DR: In this paper, the authors present results from testing and characterization of new readout components, integrating these components into a scaled-down readout system for validation of the design and technology.
Abstract: POLARBEAR-2 is a next-generation receiver for precision measurements of polarization of the cosmic microwave background, scheduled to deploy in 2015. It will feature a large focal plane, cooled to 250 milliKelvin, with 7,588 polarization-sensitive antenna-coupled transition edge sensor bolometers, read-out with frequency domain multiplexing with 32 bolometers on a single SQUID amplifier. We will present results from testing and characterization of new readout components, integrating these components into a scaled-down readout system for validation of the design and technology.
TL;DR: In this paper, the authors developed read-out electronics for the POLARBEAR-2 CMB experiment, which multiplexes 32-TES bolometers through a single superconducting quantum interface device (SQUID).
Abstract: For the next generation of Cosmic Microwave Background (CMB) experiments, kilopixel arrays of Transition Edge Sensor (TES) bolometers are necessary to achieve the required sensitivity and their science goals. We are developing read-out electronics for POLARBEAR-2 CMB experiment, which multiplexes 32-TES bolometers through a single superconducting quantum interface device (SQUID). To increase both the bandwidth of the SQUID electronics and the multiplexing factor, we are modifying cold wiring and developing LC filters, and a low-inductance superconducting cable. Using these components, we will show frequency domain multiplexing up to 3 MHz.
University of California, San Diego1, Cardiff University2, University of Colorado Boulder3, Lawrence Berkeley National Laboratory4, University of California, Berkeley5, Dalhousie University6, KEK7, McGill University8, University of Paris9, Austin College10, Imperial College London11, Princeton University12, Goddard Space Flight Center13, University of Tokyo14, Tel Aviv University15
TL;DR: The polarbear cosmic microwave background (CMB) polarization experiment has been observing since early 2012 from its 5,200 m site in the Atacama Desert in Northern Chile as discussed by the authors.
Abstract: The polarbear cosmic microwave background (CMB) polarization experiment has been observing since early 2012 from its 5,200 m site in the Atacama Desert in Northern Chile. polarbear’s measurements will characterize the expected CMB polarization due to gravitational lensing by large scale structure, and search for the possible B-mode polarization signature of inflationary gravitational waves. polarbear’s 250 mK focal plane detector array consists of 1,274 polarization-sensitive antenna-coupled bolometers, each with an associated lithographed band-defining filter and contacting dielectric lenslet, an architecture unique in current CMB experiments. The status of the polarbear instrument, its focal plane, and the analysis of its measurements are presented.
Graduate University for Advanced Studies1, University of California, San Diego2, Cardiff University3, University of Colorado Boulder4, McGill University5, Lawrence Berkeley National Laboratory6, University of California, Berkeley7, Dalhousie University8, KEK9, Paris Diderot University10, Institute for the Physics and Mathematics of the Universe11, Imperial College London12, Princeton University13, University of Chicago14, Japan Aerospace Exploration Agency15, Osaka University16
TL;DR: In this article, the authors measured basic properties of alumina, such as the index of refraction, loss tangent and thermal conductivity, and performed a cooling test of the entire optical cryostat.
Abstract: POLARBEAR-2 (PB-2) is a cosmic microwave background (CMB) polarization experiment for B-mode detection. The PB-2 receiver has a large focal plane and aperture that consists of 7588 transition edge sensor (TES) bolometers at 250 mK. The receiver consists of the optical cryostat housing reimaging lenses and infrared filters, and the detector cryostat housing TES bolometers. The large focal plane places substantial requirements on the thermal design of the optical elements at the 4K, 50K, and 300K stages. Infrared filters and lenses inside the optical cryostat are made of alumina for this purpose. We measure basic properties of alumina, such as the index of refraction, loss tangent and thermal conductivity. All results meet our requirements. We also optically characterize filters and lenses made of alumina. Finally, we perform a cooling test of the entire optical cryostat. All measured temperature values satisfy our requirements. In particular, the temperature rise between the center and edge of the alumina infrared filter at 50 K is only 2:0 ± 1:4 K. Based on the measurements, we estimate the incident power to each thermal stage. © (2014) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
TL;DR: The Polarbear-2 is a next-generation receiver for precision measurements of the polarization of the cosmic microwave background (Cosmic Microwave Background (CMB), scheduled to deploy in early 2015, on a new telescope in the Simons Array on Cerro Toco in the Atacama desert of Chile.
Abstract: POLARBEAR-2 is a next-generation receiver for precision measurements of the polarization of the cosmic microwave background (Cosmic Microwave Background (CMB)). Scheduled to deploy in early 2015, it will observe alongside the existing POLARBEAR-1 receiver, on a new telescope in the Simons Array on Cerro Toco in the Atacama desert of Chile. For increased sensitivity, it will feature a larger area focal plane, with a total of 7,588 polarization sensitive antenna-coupled Transition Edge Sensor (TES) bolometers, with a design sensitivity of 4.1 uKrt(s). The focal plane will be cooled to 250 milliKelvin, and the bolometers will be read-out with 40x frequency domain multiplexing, with 36 optical bolometers on a single SQUID amplifier, along with 2 dark bolometers and 2 calibration resistors. To increase the multiplexing factor from 8x for POLARBEAR-1 to 40x for POLARBEAR-2 requires additional bandwidth for SQUID readout and well-defined frequency channel spacing. Extending to these higher frequencies requires new components and design for the LC filters which define channel spacing. The LC filters are cold resonant circuits with an inductor and capacitor in series with each bolometer, and stray inductance in the wiring and equivalent series resistance from the capacitors can affect bolometer operation. We present results from characterizing these new readout components. Integration of the readout system is being done first on a small scale, to ensure that the readout system does not affect bolometer sensitivity or stability, and to validate the overall system before expansion into the full receiver. We present the status of readout integration, and the initial results and status of components for the full array.
10 Apr 2014
TL;DR: In this article, a micro-pattern gaseous detector known as the micro-pixel chamber (μPIC) coupled with a field-programmable-gate-array-based data acquisition system was proposed for high-intensity, pulsed spallation neutron sources.
Abstract: The realization of high-intensity, pulsed spallation neutron sources such as J-PARC in Japan and SNS in the US has brought time-of-flight (TOF) based neutron techniques to the fore and spurred the development of new detector technologies. When combined with high-resolution imaging, TOF-based methods become powerful tools for direct imaging of material properties, including crystal structure/internal strain, isotopic/temperature distributions, and internal and external magnetic fields. To carry out such measurements in the high-intensities and high gamma backgrounds found at spallation sources, we have developed a new time-resolved neutron imaging detector employing a micro-pattern gaseous detector known as the micro-pixel chamber (μPIC) coupled with a field-programmable-gate-array-based data acquisition system. The detector combines 100μm-level (σ) spatial and sub-μs time resolutions with low gamma sensitivity of less than 10−12 and a rate capability on the order of Mcps (mega-counts-per-second). Here, we demonstrate the application of our detector to TOF-based techniques with examples of Bragg-edge transmission and neutron resonance transmission imaging (with computed tomography) carried out at J-PARC. We also consider the direct imaging of magnetic fields with our detector using polarized neutrons.
01 Jan 2014
TL;DR: In this paper, the authors presented a status of the development of microwave kinetic inductance detectors (MKIDs) for a detection of athermal phonons in a substrate, and made a rough estimation of the phonon propagation velocity of 1.1-1.3 km/s.
Abstract: We present a status of the development of microwave kinetic inductance detectors (MKIDs) for a detection of athermal phonons in a substrate. The energy deposited in the substrate is converted to athermal phonons. Athermal phonons arriving at the surface can break Cooper pairs in the MKIDs which are formed as a thin superconducting metal layer in the substrate surface. By counting the number of Cooper pairs broken and measuring the phonon arrival times, we can measure the amount of deposited energy and its position. MKIDs are suitable for the frequency-domain multiplexing readout, which enables us to readout hundreds of pixels simultaneously and, hence, to detect athermal phonons with a large detection efficiency. We fabricated MKIDs with a combination of aluminum and niobium on a silicon substrate, and then irradiated it with \(\alpha \) particles from an \(^{241}\)Am source. We detected phonons and made a rough estimation of the phonon propagation velocity of 1.1–1.3 km/s. We found that a thin insulator layer can block the phonon propagation from the substrate to the thin metal layer.
KEK1
TL;DR: Tomotake Matsumura1, Peter Ade2, Yoshiki Akiba3, Christopher Aleman4, Kam Arnold4, Matt Atlas4, Darcy Barron4, Julian Borrill6, Scott Chapman5, Yuji Chinone1, Ari Cukierman7, Matt Dobbs8, Tucker Elleflot4, Josquin Errard6, Giulio Fabbian9, Guangyuan Feng4, Adam Gilbert8, William Grainger10, Nils Halverson11, Masaya Hasegawa1, Kaori Hatt
Abstract: Tomotake Matsumura1, Peter Ade2, Yoshiki Akiba3, Christopher Aleman4, Kam Arnold4, Matt Atlas4, Darcy Barron4, Julian Borrill6, Scott Chapman5, Yuji Chinone1, Ari Cukierman7, Matt Dobbs8, Tucker Elleflot4, Josquin Errard6, Giulio Fabbian9, Guangyuan Feng4, Adam Gilbert8, William Grainger10, Nils Halverson11, Masaya Hasegawa1, Kaori Hattori1, Masashi Hazumi1, William Holzapfel7, Yasuto Hori1, Yuki Inoue3, Greg Jaehnig11, Nobuhiko Katayama12, Brian Keating4, Zigmund Kermish12, Reijo Keskitalo6, Ted Kisner6, Adrian Lee7, Frederick Matsuda4, Hideki Morii1, Stephanie Moyerman4, Michael Myers7, Marty Navaroli4, Haruki Nishino12, Takahiro Okamura1, Christian Reichart7, Paul Richards7, Colin Ross5, Kaja Rotermund5, Michael Sholl7, Praween Siritanasak4, Graeme Smecher8, Nathan Stebor4, Radek Stompor9, Jun-ichi Suzuki1, Aritoki Suzuki7, Suguru Takada14, Satoru Takakura15, Takayuki Tomaru1, Brandon Wilson4, Hiroshi Yamaguchi1, Oliver Zahn7