286 research outputs found
Other eyes: an essay on the power of the human gaze
In this thesis, I provide an account of a certain form of interpersonal self-consciousness and its role in human social life. In Part One, I argue that (i) the feeling of self-consciousness before another’s gaze, (ii) the special form of interpersonal connection constitutive of eye contact and (iii) the form of mutual openness involved in joint attention cannot be understood either as being reducible to the ontologically antecedent psychological states of each individual (as suggested by ‘The Reductive Approach’), nor in terms of an irreducible second person relation (as suggested by ‘The Second Person Approach’). Instead, I outline and defend a ‘Transactional Approach’ according to which, when I feel self-conscious before another’s gaze I am conscious of myself as being acted upon by the other through their gaze (Chapter One). This provides the basis for an account of eye contact as a ‘mutual transaction’ (Chapter Two) and an account of joint attention (Chapter Three). This account of joint attention, in turn, provides a basis for understanding the Aristotelian idea that human social life is distinctive in the way it is characterised by a special form of co-consciousness. In Part Two, this approach is developed to provide an account of humiliation (Chapter Four) and shame (Chapter Five). These emotions tend to be understood in terms of The Reductive Approach. However, in each instance I argue that The Reductive Approach faces serious difficulties in making sense of them and their proper place in human social life. The Transactional Approach, on the other hand, is shown to have the resources to provide a more plausible account of these emotions
Direct dialling of Haar random unitary matrices
Random unitary matrices find a number of applications in quantum information
science, and are central to the recently defined boson sampling algorithm for
photons in linear optics. We describe an operationally simple method to
directly implement Haar random unitary matrices in optical circuits, with no
requirement for prior or explicit matrix calculations. Our physically-motivated
and compact representation directly maps independent probability density
functions for parameters in Haar random unitary matrices, to optical circuit
components. We go on to extend the results to the case of random unitaries for
qubits
Near-ideal spontaneous photon sources in silicon quantum photonics
While integrated photonics is a robust platform for quantum information
processing, architectures for photonic quantum computing place stringent
demands on high quality information carriers. Sources of single photons that
are highly indistinguishable and pure, that are either near-deterministic or
heralded with high efficiency, and that are suitable for mass-manufacture, have
been elusive. Here, we demonstrate on-chip photon sources that simultaneously
meet each of these requirements. Our photon sources are fabricated in silicon
using mature processes, and exploit a novel dual-mode pump-delayed excitation
scheme to engineer the emission of spectrally pure photon pairs through
intermodal spontaneous four-wave mixing in low-loss spiralled multi-mode
waveguides. We simultaneously measure a spectral purity of ,
a mutual indistinguishably of , and intrinsic
heralding efficiency. We measure on-chip quantum interference with a visibility
of between heralded photons from different sources. These
results represent a decisive step for scaling quantum information processing in
integrated photonics
Experimental Quantum Process Discrimination
Discrimination between unknown processes chosen from a finite set is
experimentally shown to be possible even in the case of non-orthogonal
processes. We demonstrate unambiguous deterministic quantum process
discrimination (QPD) of non-orthogonal processes using properties of
entanglement, additional known unitaries, or higher dimensional systems. Single
qubit measurement and unitary processes and multipartite unitaries (where the
unitary acts non-separably across two distant locations) acting on photons are
discriminated with a confidence of in all cases.Comment: 4 pages, 3 figures, comments welcome. Revised version includes
multi-partite QP
Observation of quantum interference as a function of Berry's phase in a complex Hadamard optical network
Emerging models of quantum computation driven by multi-photon quantum
interference, while not universal, may offer an exponential advantage over
classical computers for certain problems. Implementing these circuits via
geometric phase gates could mitigate requirements for error correction to
achieve fault tolerance while retaining their relative physical simplicity. We
report an experiment in which a geometric phase is embedded in an optical
network with no closed-loops, enabling quantum interference between two photons
as a function of the phase.Comment: Comments welcom
Socioeconomic deprivation as measured by the index of multiple deprivation and its association with low sex hormone binding globulin in women
ACKNOWLEDGEMENTS M.L., I.L. and A.H.H. participated in the study concept and design, acquisition of data, study analysis, interpretation of data, drafting of the manuscript. D.M. provided statistical expertise. R.D., A.J.H., and A.F. participated in the interpretation of data and critical revision of the manuscript.Peer reviewedPublisher PD
The Apparent Anomalous, Weak, Long-Range Acceleration of Pioneer 10 and 11
Recently we reported that radio Doppler data generated by NASA's Deep Space
Network (DSN) from the Pioneer 10 and 11 spacecraft indicate an apparent
anomalous, constant, spacecraft acceleration with a magnitude cm s, directed towards the Sun (gr-qc/9808081). Analysis of
similar Doppler and ranging data from the Galileo and Ulysses spacecraft
yielded ambiguous results for the anomalous acceleration, but it was useful in
that it ruled out the possibility of a systematic error in the DSN Doppler
system that could easily have been mistaken as a spacecraft acceleration. Here
we present some new results, including a critique suggestions that the
anomalous acceleration could be caused by collimated thermal emission. Based
partially on a further data for the Pioneer 10 orbit determination, the data
now spans January 1987 to July 1998, our best estimate of the average Pioneer
10 acceleration directed towards the Sun is cm
s.Comment: Latex, 7 pages and 2 figures. Invited talk at the XXXIV-th Rencontres
de Moriond Meeting on Gravitational Waves and Experimental Gravity. Les Arcs,
Savoi, France (January 23-30,1999). Corrected typo
Generation and sampling of quantum states of light in a silicon chip
Implementing large instances of quantum algorithms requires the processing of
many quantum information carriers in a hardware platform that supports the
integration of different components. While established semiconductor
fabrication processes can integrate many photonic components, the generation
and algorithmic processing of many photons has been a bottleneck in integrated
photonics. Here we report the on-chip generation and processing of quantum
states of light with up to eight photons in quantum sampling algorithms.
Switching between different optical pumping regimes, we implement the
Scattershot, Gaussian and standard boson sampling protocols in the same silicon
chip, which integrates linear and nonlinear photonic circuitry. We use these
results to benchmark a quantum algorithm for calculating molecular vibronic
spectra. Our techniques can be readily scaled for the on-chip implementation of
specialised quantum algorithms with tens of photons, pointing the way to
efficiency advantages over conventional computers
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