1,125 research outputs found
Photoelectrochemical cells including chalcogenophosphate photoelectrodes
Photoelectrochemical cells employing chalcogenophosphate (MPX3) photoelectrodes are described where M is selected from the group of transition metal series of elements beginning with scandium (atomic number 21) through germanium (atomic number 32) yttrium (atomic number 39) through antimony (atomic number 51) and lanthanum (atomic number 57) through polonium (atomic number 84); P is phosphorus; and X is selected from the chalogenide series consisting of sulfur, selenium, and tellurium. These compounds have bandgaps in the desirable range from 2.0 eV to 2.2 eV for the photoelectrolysis of water and are stable when used as photoelectrodes for the same
Relaxation Patterns in Supercooled Liquids from Generalized Mode-Coupling Theory
The mode-coupling theory of the glass transition treats the dynamics of
supercooled liquids in terms of two-point density correlation functions. Here
we consider a generalized, hierarchical formulation of schematic mode-coupling
equations in which the full basis of multipoint density correlations is taken
into account. By varying the parameters that control the effective
contributions of higher-order correlations, we show that infinite hierarchies
can give rise to both sharp and avoided glass transitions. Moreover, small
changes in the form of the coefficients result in different scaling behaviors
of the structural relaxation time, providing a means to tune the fragility in
glass-forming materials. This demonstrates that the infinite-order construct of
generalized mode-coupling theory constitutes a powerful and unifying framework
for kinetic theories of the glass transition
Conductivity of disordered quantum lattice models at infinite temperature: Many-body localization
We reinvestigate the behavior of the conductivity of several disordered
quantum lattice models at infinite temperature using exact diagonalization.
Contrary to the conclusion drawn in a recent investigation of similar
quantities in identical systems, we find evidence of a localized regime for
strong random fields. We estimate the location of the critical field for the
many-body localization transition for the random-field XXZ spin chain, and
compare our findings with recent investigations in related systems.Comment: 5 pages, 4 figures. Accepted for publication in Phys. Rev.
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