4,968 research outputs found
Preliminary evaluation of a thin organic film coating Final report
High temperature and humidity resistance of thin siloxane films on metal substrate
Circuit QED and sudden phase switching in a superconducting qubit array
Superconducting qubits connected in an array can form quantum many-body
systems such as the quantum Ising model. By coupling the qubits to a
superconducting resonator, the combined system forms a circuit QED system.
Here, we study the nonlinear behavior in the many-body state of the qubit array
using a semiclassical approach. We show that sudden switchings as well as a
bistable regime between the ferromagnetic phase and the paramagnetic phase can
be observed in the qubit array. A superconducting circuit to implement this
system is presented with realistic parameters .Comment: 4 pages, 3 figures, submitted for publication
Riccati parameter modes from Newtonian free damping motion by supersymmetry
We determine the class of damped modes \tilde{y} which are related to the
common free damping modes y by supersymmetry. They are obtained by employing
the factorization of Newton's differential equation of motion for the free
damped oscillator by means of the general solution of the corresponding Riccati
equation together with Witten's method of constructing the supersymmetric
partner operator. This procedure leads to one-parameter families of (transient)
modes for each of the three types of free damping, corresponding to a
particular type of %time-dependent angular frequency. %time-dependent,
antirestoring acceleration (adding up to the usual Hooke restoring
acceleration) of the form a(t)=\frac{2\gamma ^2}{(\gamma t+1)^{2}}\tilde{y},
where \gamma is the family parameter that has been chosen as the inverse of the
Riccati integration constant. In supersymmetric terms, they represent all those
one Riccati parameter damping modes having the same Newtonian free damping
partner modeComment: 6 pages, twocolumn, 6 figures, only first 3 publishe
Telecommunications system design for the Mariner Mars 1971 spacecraft
The configuration of the Mariner Mars 1971 spacecraft telecommunications system is detailed, with particular attention to modifications performed to accommodate the orbital mission. The analysis and planning for launching are also discussed
Cosmogenic Ar-36 from neutron capture by Cl-35 in the Chico L6 chondrite: Additional evidence for large shielding
The cosmic ray produced Ar-36/Ar-38 ratio measured in iron meteorites is about 0.65, but is not well determined for stone meteorites due to the common presence of trapped Ar or absorbed atmospheric Ar in bulk analysis. Almost all single-extraction measurements of stones give Ar-36/Ar-38 ratios intermediate between the trapped and air values of 5.3 and the expected cosmogenic value of about 0.65. The isotopic composition of Ar was measured for stepwise temperature release of both chondritic and melt portions of Chico. The Chico data suggest that for large chondrites, the cosmogenic Ar-36/Ar-38 ratio may well be higher than 0.65, and therefore the procedure of correcting bulk analysis results may underestimate the concentration of cosmogenic Ar-38. In this context we note that in analysis of many Antarctic chondrites observed that determined amounts of cosmogenic Ar-38 averaged about 13 percent too low in comparison to that expected from measurements of other cosmogenic species
Pauli's Theorem and Quantum Canonical Pairs: The Consistency Of a Bounded, Self-Adjoint Time Operator Canonically Conjugate to a Hamiltonian with Non-empty Point Spectrum
In single Hilbert space, Pauli's well-known theorem implies that the
existence of a self-adjoint time operator canonically conjugate to a given
Hamiltonian signifies that the time operator and the Hamiltonian possess
completely continuous spectra spanning the entire real line. Thus the
conclusion that there exists no self-adjoint time operator conjugate to a
semibounded or discrete Hamiltonian despite some well-known illustrative
counterexamples. In this paper we evaluate Pauli's theorem against the single
Hilbert space formulation of quantum mechanics, and consequently show the
consistency of assuming a bounded, self-adjoint time operator canonically
conjugate to a Hamiltonian with an unbounded, or semibounded, or finite point
spectrum. We point out Pauli's implicit assumptions and show that they are not
consistent in a single Hilbert space. We demonstrate our analysis by giving two
explicit examples. Moreover, we clarify issues sorrounding the different
solutions to the canonical commutation relations, and, consequently, expand the
class of acceptable canonical pairs beyond the solutions required by Pauli's
theorem.Comment: contains corrections to minor typographical errors of the published
versio
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