1,009 research outputs found
The frictional Schr\"odinger-Newton equation in models of wave function collapse
Replacing the Newtonian coupling G by -iG, the Schrodinger-Newton equation
becomes ``frictional''. Instead of the reversible Schrodinger-Newton equation,
we advocate its frictional version to generate the set of pointer states for
macroscopic quantum bodies.Comment: 6pp LaTeX for J.Phys.Conf.Ser.+2 figs. Talk given at the Int.
Workshop DICE2006 "Quantum Mechanics between Decoherence and Determinism: new
aspects from particle physics to cosmology" Piombino, Sept 11-15, 200
Convergence of the Magnus series
The Magnus series is an infinite series which arises in the study of linear
ordinary differential equations. If the series converges, then the matrix
exponential of the sum equals the fundamental solution of the differential
equation. The question considered in this paper is: When does the series
converge? The main result establishes a sufficient condition for convergence,
which improves on several earlier results.Comment: 11 pages; v2: added justification for conjecture, minor
clarifications and correction
Low-temperature tapered-fiber probing of diamond NV ensembles coupled to GaP microcavities
In this work we present a platform for testing the device performance of a
cavity-emitter system, using an ensemble of emitters and a tapered optical
fiber. This method provides high-contrast spectra of the cavity modes,
selective detection of emitters coupled to the cavity, and an estimate of the
device performance in the single- emitter case. Using nitrogen-vacancy (NV)
centers in diamond and a GaP optical microcavity, we are able to tune the
cavity onto the NV resonance at 10 K, couple the cavity-coupled emission to a
tapered fiber, and measure the fiber-coupled NV spontaneous emission decay.
Theoretically we show that the fiber-coupled average Purcell factor is 2-3
times greater than that of free-space collection; although due to ensemble
averaging it is still a factor of 3 less than the Purcell factor of a single,
ideally placed center.Comment: 15 pages, 6 figure
Notes on Certain Newton Gravity Mechanisms of Wave Function Localisation and Decoherence
Both the additional non-linear term in the Schr\"odinger equation and the
additional non-Hamiltonian term in the von Neumann equation, proposed to ensure
localisation and decoherence of macro-objects, resp., contain the same
Newtonian interaction potential formally. We discuss certain aspects that are
common for both equations. In particular, we calculate the enhancement of the
proposed localisation and/or decoherence effects, which would take place if one
could lower the conventional length-cutoff and resolve the mass density on the
interatomic scale.Comment: 8pp LaTex, Submitted to J. Phys. A: Math-Gen, for the special issue
``The Quantum Universe'' in honor of G. C. Ghirard
Delayed presentation of an isolated gallbladder rupture following blunt abdominal trauma: a case report
This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
Fabrication of Triangular Nanobeam Waveguide Networks in Bulk diamond Using Single-Crystal Silicon Hard Masks
A scalable approach for integrated photonic networks in single-crystal
diamond using triangular etching of bulk samples is presented. We describe
designs of high quality factor (Q=2.51x10^6) photonic crystal cavities with low
mode volume (Vm=1.062x({\lambda}/n)^3), which are connected via waveguides
supported by suspension structures with predicted transmission loss of only
0.05 dB. We demonstrate the fabrication of these structures using transferred
single-crystal silicon hard masks and angular dry etching, yielding photonic
crystal cavities in the visible spectrum with measured quality factors in
excess of Q=3x103.Comment: This article will be published in Applied Physics Letter
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