Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
2008-8-7
pubmed:abstractText
The submillimetre or terahertz region of the electromagnetic spectrum contains approximately half of the total luminosity of the Universe and 98% of all the photons emitted since the Big Bang. This radiation is strongly absorbed in the Earth's atmosphere, so space-based terahertz telescopes are crucial for exploring the evolution of the Universe. Thermal emission from the primary mirrors in these telescopes can be reduced below the level of the cosmic background by active cooling, which expands the range of faint objects that can be observed. However, it will also be necessary to develop bolometers-devices for measuring the energy of electromagnetic radiation-with sensitivities that are at least two orders of magnitude better than the present state of the art. To achieve this sensitivity without sacrificing operating speed, two conditions are required. First, the bolometer should be exceptionally well thermally isolated from the environment; second, its heat capacity should be sufficiently small. Here we demonstrate that these goals can be achieved by building a superconducting hot-electron nanobolometer. Its design eliminates the energy exchange between hot electrons and the leads by blocking electron outdiffusion and photon emission. The thermal conductance between hot electrons and the thermal bath, controlled by electron-phonon interactions, becomes very small at low temperatures ( approximately 1 x 10-16 W K-1 at 40 mK). These devices, with a heat capacity of approximately 1 x 10-19 J K-1, are sufficiently sensitive to detect single terahertz photons in submillimetre astronomy and other applications based on quantum calorimetry and photon counting.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
1748-3395
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
3
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
496-500
pubmed:meshHeading
pubmed-meshheading:18685638-Astronomy, pubmed-meshheading:18685638-Electromagnetic Fields, pubmed-meshheading:18685638-Electrons, pubmed-meshheading:18685638-Energy Transfer, pubmed-meshheading:18685638-Equipment Design, pubmed-meshheading:18685638-Hot Temperature, pubmed-meshheading:18685638-Nanotechnology, pubmed-meshheading:18685638-Niobium, pubmed-meshheading:18685638-Photons, pubmed-meshheading:18685638-Physics, pubmed-meshheading:18685638-Piperidones, pubmed-meshheading:18685638-Polymethyl Methacrylate, pubmed-meshheading:18685638-Sensitivity and Specificity, pubmed-meshheading:18685638-Silicon, pubmed-meshheading:18685638-Silicon Compounds, pubmed-meshheading:18685638-Silicon Dioxide, pubmed-meshheading:18685638-Surface Properties, pubmed-meshheading:18685638-Thermal Conductivity, pubmed-meshheading:18685638-Titanium
pubmed:year
2008
pubmed:articleTitle
Ultrasensitive hot-electron nanobolometers for terahertz astrophysics.
pubmed:publicationType
Letter, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't