On the anomalous mass defect of strange stars in the Field Correlator Method

We investigate general aspects of the mass defects of strange stars in the context of the Field Correlator Method, without magnetic field. The main parameters of the model that enter the corresponding nonperturbative equation of state of the quark gluon plasma are the gluon condensate $G_2$ and the large distance static $Q{\bar Q}$ potential $V_1$. We calculate mass defects of stellar configurations in the central density range $11<\log\rho_c<18$. In general, the mass defects are strongly dependent on the model parameters. For a large range of values of $G_2$ and $V_1$, we obtain anomalous mass defects with magnitudes around $10^{53}\,$erg\,, of the same order of the observed energies of gamma-ray bursts and neutrino emissions in SN1987A, and of the theoretically predicted energies of the quark-novae explosions.Comment: 24 pages, 6 figure

Strange stars properties calculated in the framework of the Field Correlator Method

We calculate the strange star properties in the framework of the Field Correlator Method. We find that for the values of the gluon condensate $G_2=0.006\;{\rm GeV}^4$ and $G_2=0.0068\;{\rm GeV}^4$, which give a critical temperature $T_c\sim170\;{\rm MeV}$ at $\mu_c=0$, the sequences of strange stars are compatible with some of the semi-empirical mass-radius relations and data obtained from astrophysical observations.Comment: 26 pages, 10 figure

Second harmonic spectroscopy to optically detect valley polarization in 2D materials

Valley polarization (VP), an induced imbalance in the populations of a multi-valley electronic system, allows emission of second harmonic (SH) light even in centrosymmetric crystals such as graphene. Whereas in systems such as MoS$\mathrm{_2}$ or BN this adds to their intrinsic quadratic response, SH generation in a multi-valley inversion-symmetric crystal can provide a direct measure of valley polarization. By computing the nonlinear response and characterizing theoretically the respective SH as a function of polarization, temperature, electron density, and degree of VP, we demonstrate the possibility of disentangling and individually quantifying the intrinsic and valley contributions to the SH. A specific experimental setup is proposed to obtain direct quantitative information about the degree of VP and allow its remote mapping. This approach could prove useful for direct, contactless, real-space monitoring of valley injection and other applications of valley transport and valleytronics.Comment: Updating with published version, including typesetting corrections to eqs 3 and 4; 7 pages, 5 figure

Meta-Potentiation: Neuro-Astroglial Interactions Supporting Perceptual Consciousness

Conscious perceptual processing involves the sequential activation of cortical networks at several brain locations, and the onset of oscillatory synchrony affecting the same neuronal population. How do the earlier activated circuits sustain their excitation to synchronize with the later ones? We call such a sustaining process &#x22;meta-potentiation&#x22;, and propose that it depends on neuro-astroglial interactions. In our proposed model, attentional cholinergic and stimulus-related glutamatergic inputs to astroglia elicit the release of astroglial glutamate to bind with neuronal NMDA receptors containing the NR2B subunit. Once calcium channels are open, slow inward currents activate the CaM/CaMKII complex to phosphorylate AMPA receptors in a population of neurons connected with the astrocyte, thus amplifying the local excitatory pattern to participate in a larger synchronized assembly that supports consciousness

Superlattice nonlinearities for Gigahertz-Terahertz generation in harmonic multipliers

Semiconductor superlattices are strongly nonlinear media offering several technological challenges associated with the generation of high-frequency Gigahertz radiation and very effective frequency multiplication up to several Terahertz. However, charge accumulation, traps and interface defects lead to pronounced asymmetries in the nonlinear current flow, from which high harmonic generation stems. This problem requires a full non-perturbative solution of asymmetric current flow under irradiation, which we deliver in this paper within the Boltzmann-Bloch approach. We investigate the nonlinear output on both frequency and time domains and demonstrate a significant enhancement of even harmonics by tuning the interface quality. Moreover, we find that increasing arbitrarily the input power is not a solution for high nonlinear output, in contrast with materials described by conventional susceptibilities. There is a complex combination of asymmetry and power values leading to maximum high harmonic generation.Comment: 13 pages, 7 figures, Accepted for Nanophotonics (De Gruyter