31,024 research outputs found

    Golan v. Holder: Copyright in the Image of the First Amendment

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    Does copyright violate the First Amendment? Professor Melville Nimmer asked this question forty years ago, and then answered it by concluding that copyright itself is affirmatively speech protective. Despite ample reason to doubt Nimmer’s response, the Supreme Court has avoided an independent, thoughtful, plenary review of the question. Copyright has come to enjoy an all-but-categorical immunity to First Amendment constraints. Now, however, the Court faces a new challenge to its back-of-the-hand treatment of this vital conflict. In Golan v. Holder the Tenth Circuit considered legislation (enacted pursuant to the Berne Convention and TRIPS) “restoring” copyright protection to millions of foreign works previously thought to belong to the public domain. The Tenth Circuit upheld the legislation, but not without noting that it appeared to raise important First Amendment concerns. The Supreme Court granted certiorari. This article addresses the issues in the Golan case, literally on the eve of oral argument before the Court. This article first considers the Copyright and Treaty Clauses, and then addresses the relationship between copyright and the First Amendment. The discussion endorses an understanding of that relationship in which the Amendment is newly seen as paramount, and copyright is newly seen in the image of the Amendment

    Emissivity measurements of reflective surfaces at near-millimeter wavelengths

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    We have developed an instrument for directly measuring the emissivity of reflective surfaces at near-millimeter wavelengths. The thermal emission of a test sample is compared with that of a reference surface, allowing the emissivity of the sample to be determined without heating. The emissivity of the reference surface is determined by one’s heating the reference surface and measuring the increase in emission. The instrument has an absolute accuracy of Δe = 5 x 10^-4 and can reproducibly measure a difference in emissivity as small as Δe = 10^-4 between flat reflective samples. We have used the instrument to measure the emissivity of metal films evaporated on glass and carbon fiber-reinforced plastic composite surfaces. We measure an emissivity of (2.15 ± 0.4) x 10^-3 for gold evaporated on glass and (2.65 ± 0.5) x 10^-3 for aluminum evaporated on carbon fiber-reinforced plastic composite

    First-principles calculations of the vibrational properties of bulk CdSe and CdSe nanowires

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    We present first-principles calculations on bulk CdSe and CdSe nanowires with diameters of up to 22 \AA. Density functional linear combination of atomic orbitals and plane wave calculations of the electronic and structural properties are presented and discussed. We use an iterative, symmetry-based method to relax the structures into the ground state. We find that the band gap depends on surface termination. Vibrational properties in the whole Brillouin zone of bulk CdSe and the zone-center vibrations of nanowires are calculated and analyzed. We find strongly size-dependent and nearly constant modes, depending on the displacement directions. A comparison with available experimental Raman data is be given

    Entanglement genesis by ancilla-based parity measurement in 2D circuit QED

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    We present an indirect two-qubit parity meter in planar circuit quantum electrodynamics, realized by discrete interaction with an ancilla and a subsequent projective ancilla measurement with a dedicated, dispersively coupled resonator. Quantum process tomography and successful entanglement by measurement demonstrate that the meter is intrinsically quantum non-demolition. Separate interaction and measurement steps allow commencing subsequent data qubit operations in parallel with ancilla measurement, offering time savings over continuous schemes.Comment: 5 pages, 4 figures; supplemental material with 5 figure

    Composite infrared bolometers with Si_3N_4 micromesh absorbers

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    We report the design and performance of 300-mK composite bolometers that use micromesh absorbers and support structures patterned from thin films of low-stress silicon nitride. The small geometrical filling factor of the micromesh absorber provides 20× reduction in heat capacity and cosmic ray cross section relative to a solid absorber with no loss in IR-absorption efficiency. The support structure is mechanically robust and has a thermal conductance, G < 2 × 10^(−11) W/K, which is four times smaller than previously achieved at 300 mK. The temperature rise of the bolometer is measured with a neutron transmutation doped germanium thermistor attached to the absorbing mesh. The dispersion in electrical and thermal parameters of a sample of 12 bolometers optimized for the Sunyaev–Zel’dovich Infrared Experiment is ±7% in R (T), ±5% in optical efficiency, and ±4% in G

    RSFQ devices with selective dissipation for quantum information processing

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    We study the possibility to use frequency dependent damping in RSFQ circuits as means to reduce dissipation and consequent decoherence in RSFQ/qubit circuits. We show that stable RSFQ operation can be achieved by shunting the Josephson junctions with an RCRC circuit instead of a plain resistor. We derive criteria for the stability of such an arrangement, and discuss the effect on decoherence and the optimisation issues. We also design a simple flux generator aimed at manipulating flux qubits

    Resolving Non-Determinism in Choreographies

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    Resolving non-deterministic choices of choreographies is a crucial task. We introduce a novel notion of realisability for choreographies –called whole-spectrum implementation– that rules out deterministic implementations of roles that, no matter which context they are placed in, will never follow one of the branches of a non-deterministic choice. We show that, under some conditions, it is decidable whether an implementation is whole-spectrum. As a case study, we analyse the POP protocol under the lens of whole-spectrum implementation

    Satisfying the Einstein-Podolsky-Rosen criterion with massive particles

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    In 1935, Einstein, Podolsky and Rosen (EPR) questioned the completeness of quantum mechanics by devising a quantum state of two massive particles with maximally correlated space and momentum coordinates. The EPR criterion qualifies such continuous-variable entangled states, where a measurement of one subsystem seemingly allows for a prediction of the second subsystem beyond the Heisenberg uncertainty relation. Up to now, continuous-variable EPR correlations have only been created with photons, while the demonstration of such strongly correlated states with massive particles is still outstanding. Here, we report on the creation of an EPR-correlated two-mode squeezed state in an ultracold atomic ensemble. The state shows an EPR entanglement parameter of 0.18(3), which is 2.4 standard deviations below the threshold 1/4 of the EPR criterion. We also present a full tomographic reconstruction of the underlying many-particle quantum state. The state presents a resource for tests of quantum nonlocality and a wide variety of applications in the field of continuous-variable quantum information and metrology.Comment: 8 pages, 7 figure

    0.75 atoms improve the clock signal of 10,000 atoms

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    Since the pioneering work of Ramsey, atom interferometers are employed for precision metrology, in particular to measure time and to realize the second. In a classical interferometer, an ensemble of atoms is prepared in one of the two input states, whereas the second one is left empty. In this case, the vacuum noise restricts the precision of the interferometer to the standard quantum limit (SQL). Here, we propose and experimentally demonstrate a novel clock configuration that surpasses the SQL by squeezing the vacuum in the empty input state. We create a squeezed vacuum state containing an average of 0.75 atoms to improve the clock sensitivity of 10,000 atoms by 2.05 dB. The SQL poses a significant limitation for today's microwave fountain clocks, which serve as the main time reference. We evaluate the major technical limitations and challenges for devising a next generation of fountain clocks based on atomic squeezed vacuum.Comment: 9 pages, 6 figure

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