31,400 research outputs found
Polarization Measurements and the Pairing Gap in the Universal Regime
We analyze recent cold-atom experiments on imbalanced Fermi systems using a
minimal model with a BCS-like superfluid phase coexisting with a normal phase.
This model is used to extract the T=0 pairing gap in the fully paired
superfluid state. The recently measured particle density profiles are in good
agreement with the theoretical predictions obtained from the universal
parameters from previous Quantum Monte Carlo calculations. We find that the T=0
pairing gap is greater than 0.4 times the Fermi energy , with a preferred
value of . The ratio of the pairing gap to the
Fermi Energy is larger here than in any other system of strongly-paired
fermions in which individual pairs are unbound.Comment: 4 pages, 3 figures. Revised verison includes cosmetic changes to the
text and figures. One reference adde
Phase-field modelling of fracture in single crystal plasticity
We propose a phase-field model for ductile fracture in a single crystal within the kinematically linear
regime, by combining the theory of single crystal plasticity as formulated in Gurtin et al. (2010) and
the phase-field formulation for ductile fracture proposed by Ambati et al. (2015) . The model introduces
coupling between plasticity and fracture through the dependency of the so-called degradation function
from a scalar global measure of the accumulated plastic strain on all slip systems. A viscous regularization
is introduced both in the treatment of plasticity and in the phase-field evolution equation. Testing of
the model on two examples for face centred cubic single crystals indicates that fracture is predicted to
initiate and develop in the regions of the maximum accumulated plastic strain, which is in agreement
with phenomenological observations. A rotation of the crystallographic unit cell is shown to affect the
test results in terms of failure pattern and corresponding global and local response
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From Coherent States In Adjacent Graphene Layers Toward Low-Power Logic Circuits
Colleagues and we recently proposed a new type of transistor, a Bilayer PseudoSpin Field Effect Transistor (BiSFET), based on many-body coherent states in coupled electron and hole layers in graphene. Here we review the basic BiSFET device concept and ongoing efforts to determine how such a device, which would be far from a drop-in replacement for MOSFETs in CMOS logic, could be used for low-power logic operation, and to model the effects of engineerable device parameters on the formation and gating of interlayer coherent state.Electrical and Computer Engineerin
DECOMPOSITION OF INCOME DISTRIBUTION AMONG FARM FAMILIES
The greater reliance of U.S. farm families on off-farm income has implications for the structure of agriculture and the distribution of income within agriculture. Using annual data on farm households from the Current Population Survey, the degree of income inequality for the U.S. and by region is assessed for 1984. The distribution of income among farm families is decomposed by income source. Off-farm income is shown to contribute to higher average incomes and reduce income inequality at the margin, but only in regions where full-time farming predominates. In the Northeast and South, increases in off-farm income increase regional income inequality.Consumer/Household Economics,
Time Delay Induced Death in Coupled Limit Cycle Oscillators
We investigate the dynamical behaviour of two limit cycle oscillators that
interact with each other via time delayed coupling and find that time delay can
lead to amplitude death of the oscillators even if they have the same
frequency. We demonstrate that this novel regime of amplitude "death" also
exists for large collections of coupled identical oscillators and provide
quantitative measures of this death region in the parameter space of coupling
strength and time delay. Its implication for certain biological and physical
applications is also pointed out.Comment: 4 aps formatted revtex pages; 3 figures; to be published in Phys.
Rev. Let
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