Equation of motion for multiqubit entanglement in multiple independent noisy channels

We investigate the possibility and conditions to factorize the entanglement evolution of a multiqubit system passing through multi-sided noisy channels. By means of a lower bound of concurrence (LBC) as entanglement measure, we derive an explicit formula of LBC evolution of the N-qubit generalized Greenberger-Horne-Zeilinger (GGHZ) state under some typical noisy channels, based on which two kinds of factorizing conditions for the LBC evolution are presented. In this case, the time-dependent LBC can be determined by a product of initial LBC of the system and the LBC evolution of a maximally entangled GGHZ state under the same multi-sided noisy channels. We analyze the realistic situations where these two kinds of factorizing conditions can be satisfied. In addition, we also discuss the dependence of entanglement robustness on the number of the qubits and that of the noisy channels.Comment: 14 page

High On-Off Ratio Bilayer Graphene Complementary Field Effect Transistors

In this paper, we propose a novel S/D engineering for dual-gated Bilayer Graphene (BLG) Field Effect Transistor (FET) using doped semiconductors (with a bandgap) as source and drain to obtain unipolar complementary transistors. To simulate the device, a self-consistent Non-Equilibrium Green's Function (NEGF) solver has been developed and validated against published experimental data. Using the simulator, we predict an on-off ratio in excess of $10^4$ and a subthreshold slope of ~110mV/decade with excellent scalability and current saturation, for a 20nm gate length unipolar BLG FET. However, the performance of the proposed device is found to be strongly dependent on the S/D series resistance effect. The obtained results show significant improvements over existing reports, marking an important step towards bilayer graphene logic devices.Comment: 4 pages, 11 figure

Quasi-exactly solvable cases of the N-dimensional symmetric quartic anharmonic oscillator

The O(N) invariant quartic anharmonic oscillator is shown to be exactly solvable if the interaction parameter satisfies special conditions. The problem is directly related to that of a quantum double well anharmonic oscillator in an external field. A finite dimensional matrix equation for the problem is constructed explicitly, along with analytical expressions for some excited states in the system. The corresponding Niven equations for determining the polynomial solutions for the problem are given.Comment: 7 pages, RevTeX4. A discussion on the N=1 case has been added with the boundary condition properly treate

Early Cenozoic partial melting of meta-sedimentary rocks of the eastern Gangdese arc, southern Tibet, and its contribution to syn-collisional magmatism

Continental magmatic arcs are characterized by the accretion of voluminous mantle-derived magmatic rocks and the growth of juvenile crust. However, significant volumes of meta-sedimentary rocks occur in the middle and lower arc crust, and the contributions of these rocks to the evolution of arc crust remain unclear. In this paper, we conduct a systematic study of petrology, geochronology, and geochemistry of migmatitic paragneisses from the eastern Gangdese magmatic arc, southern Tibet. The results show that the paragneisses were derived from late Carboniferous greywacke, and underwent an early Cenozoic (69–41 Ma) upper amphibolite-facies metamorphism and partial melting at pressure-temperature conditions of ~11 kbar and ~740 °C, and generated granitic melts with enriched Hf isotopic compositions (anatectic zircon εHf(t) = −10.57 to +0.78). Combined with the existing results, we conclude that the widely distributed meta-sedimentary rocks in the eastern Gangdese arc deep crust have the same protolith ages of late Carboniferous, and record northwestward-decreasing metamorphic conditions. We consider that the deeply buried sedimentary rocks resulted in the compositional change of juvenile lower crust from mafic to felsic and the formation of syn-collisional S-type granitoids. The mixing of melts derived from mantle, juvenile lower crust, and ancient crustal materials resulted in the isotopic enrichment of the syn-collisional arc-type magmatic rocks of the Gangdese arc. We suggest that crustal shortening and underthrusting, and the accretion of mantle-derived magma during the Indo-Asian collision transported the supracrustal rocks to the deep crust of the Gangdese arc

Sodium-activated potassium channels shape peripheral auditory function and activity of the primary auditory neurons in mice

Potassium (K+) channels shape the response properties of neurons. Although enormous progress has been made to characterize K+ channels in the primary auditory neurons, the molecular identities of many of these channels and their contributions to hearing in vivo remain unknown. Using a combination of RNA sequencing and single molecule fluorescent in situ hybridization, we localized expression of transcripts encoding the sodium-activated potassium channels K(Na)1.1(SLO2.2/Slack) and K(Na)1.2 (SLO2.1/Slick) to the primary auditory neurons (spiral ganglion neurons, SGNs). To examine the contribution of these channels to function of the SGNs in vivo, we measured auditory brainstem responses in K(Na)1.1/1.2 double knockout (DKO) mice. Although auditory brainstem response (wave I) thresholds were not altered, the amplitudes of suprathreshold responses were reduced in DKO mice. This reduction in amplitude occurred despite normal numbers and molecular architecture of the SGNs and their synapses with the inner hair cells. Patch clamp electrophysiology of SGNs isolated from DKO mice displayed altered membrane properties, including reduced action potential thresholds and amplitudes. These findings show that K(Na)1 channel activity is essential for normal cochlear function and suggest that early forms of hearing loss may result from physiological changes in the activity of the primary auditory neurons

Crustal evolution of a continental magmatic arc from subduction to collision: a case study in the Gangdese arc, southern Tibetan Plateau

Magmatic arcs are the main environment where continental crust is created on the post-Archean Earth; however, how juvenile arc crust evolves into mature continental crust is still controversial. In this study, we report new bulk-rock major and trace elements, Sr-Nd isotopes, and zircon U-Pb ages and Hf isotopes from a large suite of granites collected from the eastern segment of the Gangdese arc, southern Tibetan Plateau, which record a complete history of arc crust evolution from Mesozoic subduction to Cenozoic collision. These new data show that Gangdese crust-derived granites generated during the subduction to collisional stages record significant geochemical changes with age, indicating that the bulk composition, lithological makeup, and thicknesses of the arc crust evolved over time. Here, we propose that the Gangdese arc had a thick juvenile crust with a small volume of ancient crustal components during late-stage subduction of the Neo-Tethys Ocean, a thin juvenile crust with heterogeneously distributed ancient crustal materials during early collision, and a thick juvenile crust with minor proportions of ancient rocks during late collision. This implies that the arc experienced episodes of crustal thickening during the Late Cretaceous and Eocene, interspersed by periods of thinning during the Paleocene and Miocene, and several discrete episodes of partial melting in the lower arc crust, and cycling or recycling of juvenile and ancient crustal materials within the arc crust and between the crust and mantle. We suggest that shallow subduction of the Neo-Tethys during the Late Cretaceous promoted tectonic thickening of the arc crust, partial melting of lower crust, and formation of high Sr/Y granites. After the onset of the Indo-Asian collision, breakoff of the subducted Neo-Tethyan oceanic slab during the Paleocene/early Eocene allowed thinning of the overlying arc crust and generation of granites derived from juvenile and ancient crustal sources. Continued underthrusting of the Indian continental crust and subsequent delamination of thickened lithospheric mantle led to thickening and thinning of the arc crust, respectively, and partial melting of thickened lower crust and generation of high Sr/Y granites during the Oligocene and Miocene. Using the Gangdese as an analogue for post-Archean continental margins, we suggest that the repeated thickening and thinning of arc crust, and associated multistage remelting of the lower arc crust, and material cycling or recycling within the crust and between the crust and mantle from subduction to collision are common processes that drive maturation of juvenile arc crust

Pressure-induced alpha-to-omega transition in titanium metal: A systematic study of the effects of uniaxial stress

We investigated the effects of uniaxial stress on the pressure-induced alpha-to-omega transition in pure titanium (Ti) by means of angle dispersive x-ray diffraction in a diamond-anvil cell. Experiments under four different pressure environments reveal that: (1) the onset of the transition depends on the pressure medium used, going from 4.9 GPa (no pressure medium) to 10.5 GPa (argon pressure medium); (2) the a and w phases coexist over a rather large pressure range, which depends on the pressure medium employed; (3) the hysteresis and quenchability of the w phase is affected by differences in the sample pressure environment; and (4) a short term laser-heating of Ti lowers the alpha-to-omega transition pressure. Possible transition mechanisms are discussed in the light of the present results, which clearly demonstrated the influence of uniaxial stress in the alpha-to-omega transition.Comment: 16 pages, 6 figures, 1 tabl

Operator entanglement of two-qubit joint unitary operations revisited: Schmidt number approach

Operator entanglement of two-qubit joint unitary operations is revisited. Schmidt number is an important attribute of a two-qubit unitary operation, and may have connection with the entanglement measure of the unitary operator. We found the entanglement measure of two-qubit unitary operators is classified by the Schmidt number of the unitary operators. The exact relation between the operator entanglement and the parameters of the unitary operator is clarified too.Comment: To appear in the Brazilian Journal of Physic

NF-κB mediated enhancement of potassium currents by the chemokine CXCL1/growth related oncogene in small diameter rat sensory neurons

<p>Abstract</p> <p>Background</p> <p>Inflammatory processes play important roles in both neuropathic and inflammatory pain states, but the effects of inflammation <it>per se </it>within the sensory ganglia are not well understood. The cytokine growth-related oncogene (GRO/KC; CXCL1) shows strong, rapid upregulation in dorsal root ganglion (DRG) in both nerve injury and inflammatory pain models. We examined the direct effects of GRO/KC on small diameter DRG neurons, which are predominantly nociceptive. Whole cell voltage clamp technique was used to measure voltage-activated potassium (K) currents in acutely cultured adult rat small diameter sensory neurons. Fluorescently labeled isolectin B4 (IB4) was used to classify cells as IB4-positive or IB4-negative.</p> <p>Results</p> <p>In IB4-negative neurons, voltage-activated K current densities of both transient and sustained components were increased after overnight incubation with GRO/KC (1.5 nM), without marked changes in voltage dependence or kinetics. The average values for the slow and fast decay time constants at 20 mV were unchanged by GRO/KC. The amplitude of the fast inactivating component increased significantly with no large shifts in the voltage dependence of inactivation. The increase in K currents was completely blocked by co-incubation with protein synthesis inhibitor cycloheximide (CHX) or NF-κB inhibitors pyrrolidine dithiocarbamate (PDTC) or quinazoline (6-Amino-4-(4-phenoxypheny lethylamino;QNZ). In contrast, the voltage-activated K current of IB4-positive neurons was unchanged by GRO/KC. GRO/KC incubation caused no significant changes in the expression level of eight selected voltage-gated K channel genes in quantitative PCR analysis.</p> <p>Conclusion</p> <p>The results suggest that GRO/KC has important effects in inflammatory processes via its direct actions on sensory neurons, and that activation of NF-κB is involved in the GRO/KC-induced enhancement of K currents.</p

The Mesozoic magmatic, metamorphic, and tectonic evolution of the eastern Gangdese magmatic arc, southern Tibet

Magmatic arcs are natural laboratories for studying the growth of continental crusts. The Gangdese arc, southern Tibet, is an archetypal continental magmatic arc that formed due to Mesozoic subduction of the Neo-Tethyan oceanic lithosphere; however, its formation and evolution remain controversial. In this contribution, we combine newly reported and previously published geochemical and geochronological data for Mesozoic magmatic rocks in the eastern Gangdese arc to reveal its magmatic and metamorphic histories and review its growth, thickening, and fractionation and mineralization processes. Our results show that: (1) the Gangdese arc consists of multiple Mesozoic arc-type magmatic rocks and records voluminous juvenile crustal growth. (2) The Mesozoic magmatic rocks experienced Late Cretaceous granulite-facies metamorphism and partial melting, thus producing hydrous and metallogenic element-rich migmatites that form a major component of the lower arc crust and are a potential source for the Miocene ore-hosting porphyries. (3) The Gangdese arc witnessed crustal thickening and reworking during the Middle to Late Jurassic and Late Cretaceous. (4) Crystallization-fractionation of mantle-derived magmas and partial melting of thickened juvenile lower crust induced intracrustal chemical differentiation during subduction. We suggest that the Gangdese arc underwent the following main tectonic, magmatic, and metamorphic evolution processes: normal subduction and associated mantle-derived magmatism during the Late Triassic to Jurassic; shallow subduction during the Early Cretaceous and an associated magmatic lull; and mid-oceanic ridge subduction, high-temperature metamorphism and an associated magmatic flare-up during the early Late Cretaceous, and flat subduction, high-temperature and high-pressure metamorphism, partial melting, and associated crust-derived magmatism during the late Late Cretaceous. Key issues for further research include the temporal and spatial distributions of Mesozoic magmatic rocks, the evolution of the components and compositions of arc crust over time, and the metallogenic processes that occur in such environments during subduction