Polaronic slowing of fermionic impurities in lattice Bose-Fermi mixtures

We generalize the application of small polaron theory to ultracold gases of Ref. [\onlinecite{jaksch_njp1}] to the case of Bose-Fermi mixtures, where both components are loaded into an optical lattice. In a suitable range of parameters, the mixture can be described within a Bogoliubov approach in the presence of fermionic (dynamic) impurities and an effective description in terms of polarons applies. In the dilute limit of the slow impurity regime, the hopping of fermionic particles is exponentially renormalized due to polaron formation, regardless of the sign of the Bose-Fermi interaction. This should lead to clear experimental signatures of polaronic effects, once the regime of interest is reached. The validity of our approach is analyzed in the light of currently available experiments. We provide results for the hopping renormalization factor for different values of temperature, density and Bose-Fermi interaction for three-dimensional $^{87}\rm{Rb}-^{40}\rm{K}$ mixtures in optical lattice.Comment: 13 pages, 5 figure

Magnetism and domain formation in SU(3)-symmetric multi-species Fermi mixtures

We study the phase diagram of an SU(3)-symmetric mixture of three-component ultracold fermions with attractive interactions in an optical lattice, including the additional effect on the mixture of an effective three-body constraint induced by three-body losses. We address the properties of the system in $D \geq 2$ by using dynamical mean-field theory and variational Monte Carlo techniques. The phase diagram of the model shows a strong interplay between magnetism and superfluidity. In the absence of the three-body constraint (no losses), the system undergoes a phase transition from a color superfluid phase to a trionic phase, which shows additional particle density modulations at half-filling. Away from the particle-hole symmetric point the color superfluid phase is always spontaneously magnetized, leading to the formation of different color superfluid domains in systems where the total number of particles of each species is conserved. This can be seen as the SU(3) symmetric realization of a more general tendency to phase-separation in three-component Fermi mixtures. The three-body constraint strongly disfavors the trionic phase, stabilizing a (fully magnetized) color superfluid also at strong coupling. With increasing temperature we observe a transition to a non-magnetized SU(3) Fermi liquid phase.Comment: 36 pages, 17 figures; Corrected typo

Bonnard´s representation of the perception of substance

Artists are said to be like neuroscientists able to exploit the capacities of the brain to generate aesthetic experience (Zeki, 2001). Pierre Bonnard (1867-1947) has been recognized as one of the greatest and most enigmatic masters of the 20th century painting. For his understanding of the eye movements, attentional shifts mechanism and the representation in his paintings of the complexity of the physiological process of vision perception, something that he famously referred to as "the transcription of the adventures of the optic nerve", he is considered a revolutionary painter. Our recent eye movements study on Bonnard's paintings evidences a "temporal-extended" mechanism in the control of scanpaths that refers to a progression of the scanpath pattern during repetitive viewings and supports the phenomenon of late emotional response which was one of the artist's artistic and perceptual objective

Monte Carlo study of fermionic trions in a square lattice with harmonic confinement

We investigate the strong-coupling limit of a three-component Fermi mixture in an optical lattice with attractive interactions. In this limit bound states (trions) of the three components are formed. We derive an effective Hamiltonian for these composite fermions and show that it is asymptotically equivalent to an antiferromagnetic Ising model. By using Monte-Carlo simulations, we investigate the spatial arrangement of the trions and the formation of a trionic density wave (CDW), both in a homogeneous lattice and in the presence of an additional harmonic confinement. Depending on the strength of the confinement and on the temperature, we found several scenarios for the trionic distribution, including coexistence of disordered trions with CDW and band insulator phases. Our results show that, due to a proximity effect, staggered density modulations are induced in regions of the trap where they would not otherwise be present according to the local density approximation.Comment: 10 pages, 8 figure

Autonomous Image Processing Algorithms Locate Region-of-Interests: The Mars Rover Application

In this report, we demonstrate that bottom-up IPA's, image-processing algorithms, can perform a new visual task to select and locate Regions-Of-Interests (ROIs). This task has been defined on the basis of a theory of top-down human vision, the scanpath theory. Further, using measures, Sp and Ss, the similarity of location and ordering, respectively, developed over the years in studying human perception and the active looking role of eye movements, we could quantify the efficient and efficacious manner that IPAs can imitate human vision in located ROIS. The means to quantitatively evaluate IPA performance has been an important part of our study. In fact, these measures were essential in choosing from the initial wide variety of IPAS, that particular one that best serves for a type of picture and for a required task. It should be emphasized that the selection of efficient IPAs has depended upon their correlation with actual human chosen ROIs for the same type of picture and for the same required task accomplishment

Treating depression: Psychiatric consultation in cardiology

Depression is the most common psychiatric disorder in coronary artery disease, and it can worsen cardiac outcomes. Also, cardiac disease predisposes patients to the development of depression. Assessment of depression is an important part of ongoing patient contacts. It can be easily done through the regular use of a self-report screening tool and the clinical interview. Treatment can consist of antidepressant use, psychotherapy and mindfulness-based group therapy. The antidepressants known as the selective serotonin reuptake inhibitors can generally be used safely in cardiac patients. They are a mainstay in the treatment of moderate to severe depression. Individual cognitive-behavioral therapy can treat milder forms of depression and can augment antidepressant use in more severe cases. Mindfulness-based group therapy can provide patients with additional means of handling distress while offering social contact and support, both of which are important in the treatment of depression. The use of consulting psychiatric services offers the cardiologist a collaborative team approach when treating patients with depressive illnesses

Limitations on the principle of stationary phase when it is applied to tunneling analysis

Using a recently developed procedure - multiple wave packet decomposition - here we study the phase time formulation for tunneling/reflecting particles colliding with a potential barrier. To partially overcome the analytical difficulties which frequently arise when the stationary phase method is employed for deriving phase (tunneling) time expressions, we present a theoretical exercise involving a symmetrical collision between two identical wave packets and an one-dimensional rectangular potential barrier. Summing the amplitudes of the reflected and transmitted waves - using a method we call multiple peak decomposition - is shown to allow reconstruction of the scattered wave packets in a way which allows the stationary phase principle to be recovered.Comment: 17 pages, 2 figure

Bell inequality and CP violation in the neutral kaon system

For the entangled neutral kaon system we formulate a Bell inequality sensitive to CP violation in mixing. Via this Bell inequality we obtain a bound on the leptonic CP asymmetry which is violated by experimental data. Furthermore, we connect the Bell inequality with a decoherence approach and find a lower bound on the decoherence parameter which practically corresponds to Furry's hypothesis.Comment: 10 pages, latex, no figure

Strain development and damage accumulation under ion irradiation of polycrystalline Ge-Sb-Te alloys

The atomic displacement produced by ion irradiation with 150 keV Ar+ ions has been studied in Ge1Sb2Te4 and Ge2Sb2Te5. Electrical, optical and structural measurements have been employed to characterize the induced electrical and structural modifications. At low temperature the amorphization threshold, evaluated by in situ reflectivity measurements, is independent of the composition and the crystalline structure, and it is equal to 1 x 1013 cm-2. At room temperature, at which dynamic annealing can take place, Ge2Sb2Te5 and Ge1Sb2Te4 in the rocksalt phase exhibit the same amorphization threshold (3 x 1013 cm-2). In the trigonal structure, instead, a higher fluence is required to amorphize the Ge1Sb2Te4, compared to Ge2Sb2Te5. The observed differences between the two compositions can be explained considering the effect of dynamic annealing during ion irradiation of the trigonal phase, which is characterized by the presence of van der Waals gaps. These may act as a preferential sink for the diffusion of the displaced atoms and the filling of these gaps tunes the electronic and structural properties. Filling of about 30% of the gaps produces an electronic transition from metallic to insulating behavior. By further increasing the disorder and filling more than 70% of the gaps the films convert into the rocksalt phase