1,312 research outputs found
On the Critical Behavior of the Uniform Susceptibility of a Fermi Liquid Near an Antiferromagnetic Transition with Dynamic Exponent
We compute the leading behavior of the uniform magnetic susceptibility,
, of a Fermi liquid near an antiferromagnetic transition with dynamic
exponent . Our calculation clarifies the role of triangular ``anomaly''
graphs in the theory and justifies the effective action used in previous work
\cite{Hertz}. We find that at the critical point of a two dimensional
material, with and
nonuniversal constants. For reasonable band structures we find that in a
weak coupling approximation is small and positive. Our result suggests that
the behavior observed in the quantum critical regime of underdoped high-
superconductors are difficult to explain in a theory.Comment: 12 pages, uuencoded Postscript fil
Asteroid observations and planetary atmospheres analysis
Photoelectric observations of Eros and 30 other asteroids providing information on their surface characteristics, shape, and rotation axes are reported. Photographs of 18 asteroids and 4 comets yielding accurate position information on various dates were obtained. Photometric observations were made of the Saturn satellite lapetus, and electronographic images of the Uranus and Neptune satellites were obtained experimentally with a Spectracon tube to assess photometry by that method. Planetary patrol photographs of Venus and deconvolved area scans of Uranus were taken. UBV photometry of the Galilean satellites for the period 1973-1974 was completely analyzed and accepted for publication. An improved magnitude and color index for Minas were derived from 1974 area scans. A special photomultiplier tube with a suppressor grid was incorporated into a pulse-counting photometer with special added circuitry for carrying out the observations concerning the constancy of solar system dimensions over cosmic time
Studies in planetology, including the collection and interpretation of planetary information
The value of synoptic imaging of the planets is reported. The advantage of the Large Space Telescope, as compared with ground-based telescopes and planetary orbiters and flybys, is discussed. Desirable LST camera parameters and observing strategies are considered from the standpoint of synoptic imaging
Planetary Research Center
Extensive Earth-based photography of Mars, Jupiter, and Venus is presented which monitors the atmospheric and/or surface changes that take place day to day. Color pictures are included of the 1973 dust storm on Mars, showing the daily cycle of the storm's regeneration. Martian topography, and the progress of the storm is examined. Areas most affected by the storm are summarized
Numerically Exact Long Time Behavior of Nonequilibrium Quantum Impurity Models
A Monte Carlo sampling of diagrammatic corrections to the non-crossing
approximation is shown to provide numerically exact estimates of the long-time
dynamics and steady state properties of nonequilibrium quantum impurity models.
This `bold' expansion converges uniformly in time and significantly ameliorates
the sign problem that has heretofore limited the power of real-time Monte Carlo
approaches to strongly interacting real-time quantum problems. The new approach
enables the study of previously intractable problems ranging from generic long
time nonequilibrium transport characteristics in systems with large onsite
repulsion to the direct description of spectral functions on the real frequency
axis in Dynamical Mean Field Theory
Emergent properties hidden in plane view: Strong electronic correlations at oxide interfaces
Finding new collective electronic states in materials is one of the
fundamental goals of condensed matter physics. Atomic-scale superlattices
formed from transition metal oxides are a particularly appealing hunting ground
for new physics. In bulk form, transition metal oxides exhibit a remarkable
range of magnetic, superconducting, and multiferroic phases that are of great
scientific interest and are potentially capable of providing innovative energy,
security, electronics and medical technology platforms. In superlattices new
states may emerge at the interfaces where dissimilar materials meet.
Here we illustrate the essential features that make transition metal
oxide-based heterostructures an appealing discovery platform for emergent
properties with a few selected examples, showing how charge redistributes,
magnetism and orbital polarization arises and ferroelectric order emerges from
heterostructures comprised of oxide components with nominally contradictory
behavior with the aim providing insight into the creation and control of novel
behavior at oxide interfaces by suitable mechanical, electrical or optical
boundary conditions and excitations.Comment: 16 pages, 5 figure
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