364 research outputs found
Properties of an almost localized Fermi liquid in applied magnetic field revisited: Statistically consistent Gutzwiller approach
We discuss the Hubbard model in an applied magnetic field and analyze the
properties of neutral spin-1/2 fermions within the so-called statistically
consistent Gutzwiller approximation (SGA). The magnetization curve reproduces
in a semiquantitative manner the experimental data for liquid 3 He in the
regime of moderate correlations and in the presence of small number of vacant
cells, modeled by a non-half filled-band situation, when a small number of
vacancies (up to 5%) is introduced in the virtual fcc lattice. We also present
the results for the magnetic susceptibility and the specific heat, in which a
metamagnetic-like behavior is also singled out in a non-half-filled band case
Superconducting properties of the hole-doped three-band \emph{d-p} model studied with minimal-size real-space \emph{d}-wave pairing operators
The three-band \emph{d-p} model is investigated by means of Variational
Monte-Carlo (VMC) method with the BCS-like wave-function supplemented by the
Gutzwiller and Jastrow correlators. The VMC optimization leads to -
superconducting state with a characteristic dome-like shape of the order
parameter for hole doping , in a good agreement with the
experimental observations. Also, the off-diagonal pair-pair correlation
functions, calculated within VMC, vindicates the results obtained very recently
within the diagrammatic expansion of the Gutzwiller wave function method
(DE-GWF) [cf. Phys. Rev. B \textbf{99}, 104511 (2019)]. Subsequently, the
nature of the - pairing is investigated by means of recently proposed
\emph{minimal-size real-space d-wave pairing operators} [Phys. Rev. B
\textbf{100}, 214502 (2019)]. An emergence of the long-range superconducting
ordering for both and orbitals is reported by analysing the
corresponding off-diagonal pair-pair correlation functions. The dominant
character of \emph{d-wave} pairing on orbitals is confirmed. Additionally,
the trial wave-function is used to investigate the magnetic properties of the
system. The analysis of spin-spin correlation functions is carried out and
shows antiferromagnetic , short-range order, as expected.
For the sake of completeness, the charge gap has been estimated, which for the
parent compound takes the value , and
agrees with values reported experimentally for the cuprates
Neither backward masking of T2 nor task switching is necessary for the attentional blink
Identification of the second of two targets
(T1, T2, inserted in a stream of distractors) is impaired
when presented within 500 ms after the first (attentional
blink, AB). Barring a T1-T2 task-switch, it is thought
that T2 must be backward-masked to obtain an AB
(Giesbrecht & Di Lollo, Journal of Experimental Psychology:
Human Perception and Performance, 24, 1454-
1466, 1998). We tested the hypothesis that Giesbrecht &
Di Lollo's findings were vitiated by ceiling constraints
arising from either response scale (experiment 1) or data
limitations (experiment 2). In experiment 1, digitdistractors
were replaced with pseudoletters to increase
task difficulty, bringing performance below ceiling. An
AB occurred without backward masking of T2. In
experiment 2, a ceiling-free procedure estimated the
number of noise dots needed for 80% T2 identification.
An AB was revealed: fewer noise dots were required
during the AB period than outside it. Both outcomes
confirm that an AB can be obtained without either
masking of T2 or task switching
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