14,712 research outputs found
The Electronic States of Two Oppositely doped Mott Insulators Bilayers
We study the effect of Coulomb interaction between two oppositely doped
low-dimensional tJ model systems. We exactly show that, in the one-dimensional
case, an arbitrarily weak interaction leads to the formation of charge neutral
electron-hole pairs. We then use two different mean-field theories to address
the two-dimensional case, where inter-layer excitons also form and condense. We
propose that this results in new features which have no analog in single
layers, such as the emergence of an insulating spin liquid phase. Our simple
bilayer model might have relevance to the physics of doped Mott insulator
interfaces and of the new four layer Ba2CaCu4O8 compound.Comment: 4 pages, 1 figur
Engineering Fast High-Fidelity Quantum Operations With Constrained Interactions
Understanding how to tailor quantum dynamics to achieve a desired evolution is a crucial problemin almost all quantum technologies. We present a very general method for designing high-efficiencycontrol sequences that are always fully compatible with experimental constraints on available inter-actions and their tunability. Our approach reduces in the end to finding control fields by solvinga set of time-independent linear equations. We illustrate our method by applying it to a numberof physically-relevant problems: the strong-driving limit of a two-level system, fast squeezing in aparametrically driven cavity, the leakage problem in transmon qubit gates, and the acceleration ofSNAP gates in a qubit-cavity system
Influence of temperature fluctuations on plasma turbulence investigations with Langmuir probes
The reliability of Langmuir probe measurements for plasma-turbulence
investigations is studied on GEMR gyro-fluid simulations and compared with
results from conditionally sampled I-V characteristics as well as self-emitting
probe measurements in the near scrape-off layer of the tokamak ASDEX Upgrade.
In this region, simulation and experiment consistently show coherent in-phase
fluctuations in density, plasma potential and also in electron temperature.
Ion-saturation current measurements turn out to reproduce density fluctuations
quite well. Fluctuations in the floating potential, however, are strongly
influenced by temperature fluctuations and, hence, are strongly distorted
compared to the actual plasma potential. These results suggest that
interpreting floating as plasma-potential fluctuations while disregarding
temperature effects is not justified near the separatrix of hot fusion plasmas.
Here, floating potential measurements lead to corrupted results on the ExB
dynamics of turbulent structures in the context of, e.g., turbulent particle
and momentum transport or instability identification on the basis of
density-potential phase relations
Cirurgia de obesidade: qualidade de vida e variáveis psicológicas antes e depois do tratamento cirúrgico
Optical Properties of Strained Graphene
The optical conductivity of graphene strained uniaxially is studied within
the Kubo-Greenwood formalism. Focusing on inter-band absorption, we analyze and
quantify the breakdown of universal transparency in the visible region of the
spectrum, and analytically characterize the transparency as a function of
strain and polarization. Measuring transmittance as a function of incident
polarization directly reflects the magnitude and direction of strain. Moreover,
direction-dependent selection rules permit identification of the lattice
orientation by monitoring the van-Hove transitions. These photoelastic effects
in graphene can be explored towards atomically thin, broadband optical
elements
Mercados do azeite de oliva e da azeitona de mesa no mundo e no Brasil.
bitstream/item/33109/1/Mercados-do-azeite-de-oliva.pd
- …