98 research outputs found
Flux Phase as a Dynamic Jahn-Teller Phase: Berryonic Matter in the Cuprates?
There is considerable evidence for some form of charge ordering on the
hole-doped stripes in the cuprates, mainly associated with the low-temperature
tetragonal phase, but with some evidence for either charge density waves or a
flux phase, which is a form of dynamic charge-density wave. These three states
form a pseudospin triplet, demonstrating a close connection with the E X e
dynamic Jahn-Teller effect, suggesting that the cuprates constitute a form of
Berryonic matter. This in turn suggests a new model for the dynamic Jahn-Teller
effect as a form of flux phase. A simple model of the Cu-O bond stretching
phonons allows an estimate of electron-phonon coupling for these modes,
explaining why the half breathing mode softens so much more than the full
oxygen breathing mode. The anomalous properties of provide a coupling
(correlated hopping) which acts to stabilize density wave phases.Comment: Major Revisions: includes comparisons with specific cuprate phonon
modes, 16 eps figures, revte
General practitioners’ classification of patients with medically unexplained symptoms
In encounters between general practitioners (GPs) and patients with medically
unexplained symptoms (MUS), the negotiation of the sick role is a social process.
In this process, GPs not only use traditional biomedical diagnostic tools but also
rely on their own opinions and evaluations of a patient’s particular circumstances
in deciding whether that patient is legitimately sick. The doctor is thus a
gatekeeper of legitimacy. This article presents results from a qualitative interview
study conducted in Denmark with GPs concerning their approach to patients
with MUS. We employ a symbolic interaction approach that pays special
attention to the external validation of the sick role, making GPs’ accounts of such
patients particularly relevant. One of the article’s main findings is that GPs’
criteria for judging the legitimacy of claims by those patients that present with
MUS are influenced by the extent to which GPs are able to constitute these
patients as people with social problems and problematic personality traits
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