Interacting Local Topological Markers: A one-particle density matrix approach for characterizing the topology of interacting and disordered states

While topology is a property of a quantum state itself, most existing methods for characterizing the topology of interacting phases of matter require direct knowledge of the underlying Hamiltonian. We offer an alternative by utilizing the one-particle density matrix formalism to extend the concept of the Chern, chiral, and Chern-Simons markers to include interactions. The one-particle density matrix of a free-fermion state is a projector onto the occupied bands, defining a Brillouin zone bundle of the given topological class. This is no longer the case in the interacting limit, but as long as the one-particle density matrix is gapped, its spectrum can be adiabatically flattened, connecting it to a topologically equivalent projector. The corresponding topological markers thus characterize the topology of the interacting phase. Importantly, the one-particle density matrix is defined in terms of a given state alone, making the local markers numerically favorable, and providing an invaluable tool for characterizing topology of interacting systems when only the state itself is available. To demonstrate the practical use of the markers we use the chiral marker to identify the topology of the ground state of the Majorana-XYZ model as well as the midspectrum eigenstates of the Ising-Majorana chain across the transition between the ergodic and many-body localized phases.Comment: 7 pages, 3 figure

Role of Akt and c-Jun N-terminal Kinase 2 in Apoptosis Induced by Interleukin-4 Deprivation

El copyright pertenece a The American Society for Cell Biology. The final versión of the paper is available at http://www.pubmedcentral.nih.govWe have shown previously that interleukin-4 (IL-4) protects TS1ab cells from apoptosis, but very little is known about the mechanism by which IL-4 exerts this effect. We found that Akt activity, which is dependent on phosphatidylinositol 3 kinase, is reduced in IL-4-deprived TS1ab cells. Overexpression of wild-type Akt or a constitutively active Akt mutant protects cells from IL-4 deprivation-induced apoptosis. Readdition of IL-4 before the commitment point is able to restore Akt activity. We also show expression and c-Jun N-terminal kinase 2 activation after IL-4 deprivation. Overexpression of the constitutively activated Akt mutant in IL-4-deprived cells correlates with inhibition of c-Jun N-terminal kinase 2 activity. Finally, TS1ab survival is independent of Bcl-2, Bcl-x, or Bax.Peer reviewe

Degradación del ácido acetilsalicílico en ácido acético glacial. Influencia catalítica de la presencia de ácido sulfúrico y acetato sódico en el medio

Se ha realizado un estudio de la degradación del ácido acetilsalicílico en ácido acético glacial. Asimismo se han observado las influencias catalíticas del ácido sulfúrico y del acetato sódico presentes en el medio en proporciones variables. Se calculan los valores de la constante de velocidad de la reacción de descomposición a 25ºC por espectrofluorimetría.The degradation of acetylsalicylic acid in glacial acetic acid has been studied. Likewise the catalytics influences of the presence in medium of sulfuric acid and sodium acetate in diferent proportions, is observed. The rate constant values at 2SoC of temperature are determined spectrophotofluorimetricaly

Degradación del ácido acetilsalicílico en ácido acético glacial. Influencia catalítica de la presencia de ácido sulfúrico y acetato sódico en el medio

The degradation of acetylsalicylic acid in glacial acetic acid has been studied. Likewise the catalytics influences of the presence in medium of sulfuric acid and sodium acetate in diferent proportions, is observed. The rate constant values at 25ºC of temperature are determined spectrophotofluorimetricaly.Se ha realizado un estudio de la degradación del ácido acetilsalicílico en ácido acético glacial. Asimismo se han observado las influencias catalíticas del ácido sulfúrico y del acetato sódico presentes en el medio en proporciones variables. Se calculan los valores de la constante de velocidad de la reacción de descomposición a 25ºC por espectrofluorimetría

Hidrólisis del ácido salicilsalicílico en medio fuertemente básico

Se ha estudiado la hidrólisis del ácido salicilsalicílico en medio acuoso fuertemente básico (pH = 11,6), a las temperaturas de 10, 20, 25, 30, 35, 40, 45 y 50°C. La citada reacción ha sido seguida por espectro fotometría. Se han calculado los valores de la costante de velocidad así como los parámetros termodinámicos correspondientes al proceso global

Hidrólisis del ácido salicilsalicílico en medio fuertemente básico

Se ha estudiado la hidrólisis del ácido salicilsalicílico en medio acuoso fuertemente básico (pH = 11,6), a las temperaturas de 10, 20, 25, 30, 35, 40, 45 y 50°C. La citada reacción ha sido seguida por espectro fotometría. Se han calculado los valores de la costante de velocidad así como los parámetros termodinámicos correspondientes al proceso global

Dielectric relaxations in poly(glycidyl phenyl ether): Effects of microstructure and cyclic topology

Cyclic and linear, isoregic and aregic, and isotactic and atactic poly(glycidyl phenyl ether) (PGPE) with molecular weights up to Mw = 5.5 kg/mol are synthesized by ring-opening polymerization of glycidyl phenyl ether. Initiation with tetrabutylammonium fluoride leads to isoregic linear polymers with ~95% regular linkages, and initiation with B(C6F5)3 and B(C6F5)3/water leads to aregic cyclic and linear polymers, respectively, with ~50% regular linkages as quantified by 13C NMR. Local, segmental, and chain dynamics in PGPE is investigated by broadband dielectric spectroscopy (10–2–106 Hz). The ß-relaxation for linear PGPE is separated into two contributions arising from the motions of side groups and end groups with activation energies of 35.4 and 23.8 kJ/mol, respectively. The ß-relaxation process for cyclic PGPE shows the same activation energy as that shown by the side-group contribution in linear PGPE, indicating that topology does not play a key role on the side-group local dynamics. Moreover, cyclic PGPE samples show higher calorimetric and dynamic glass transition temperatures as well as lower dynamic fragility compared to linear chains. Unexpectedly from topological considerations, cyclic PGPE shows low frequency dielectric contributions that can be attributed to short wavelength internal ring motions and that are detectable by dielectric relaxation due to the aregic nature of the rings.Peer ReviewedPostprint (author's final draft

Europium Underneath Graphene on Ir(111): Intercalation Mechanism, Magnetism, and Band Structure

The intercalation of Eu underneath Gr on Ir(111) is comprehensively investigated by microscopic, magnetic, and spectroscopic measurements, as well as by density functional theory. Depending on the coverage, the intercalated Eu atoms form either a $(2 \times 2)$ or a $(\sqrt{3} \times \sqrt{3})$R$30^{\circ}$ superstructure with respect to Gr. We investigate the mechanisms of Eu penetration through a nominally closed Gr sheet and measure the electronic structures and magnetic properties of the two intercalation systems. Their electronic structures are rather similar. Compared to Gr on Ir(111), the Gr bands in both systems are essentially rigidly shifted to larger binding energies resulting in n-doping. The hybridization of the Ir surface state $S_1$ with Gr states is lifted, and the moire superperiodic potential is strongly reduced. In contrast, the magnetic behavior of the two intercalation systems differs substantially as found by X-ray magnetic circular dichroism. The $(2 \times 2)$ Eu structure displays plain paramagnetic behavior, whereas for the $(\sqrt{3} \times \sqrt{3})$R$30^{\circ}$ structure the large zero-field susceptibility indicates ferromagnetic coupling, despite the absence of hysteresis at 10 K. For the latter structure, a considerable easy-plane magnetic anisotropy is observed and interpreted as shape anisotropy.Comment: 18 pages with 14 figures, including Supplemental Materia

Cinética de la descomposición del ácido acetilsalicílico en disoluciones de etanol-ácido sulfúrico

Se ha determinado la constante de velocidad de la descomposición de ácido acetil salicílico en mezclas de etanol absoluto-ácido sulfúrico, mediante la evaluación espectroftuorimétrica del ácido salicílico liberado. Las medidas se han efectuado a las temperaturas de 20°, 25°, 30°, 35° y 40°C en disolución de etanol-ácido sulfúrico al 4% en ácido sulfúrico y a 25°C para disoluciones al 1%, 2%, 4%, 8% y 12% de ácido sulfúrico. Se describe la fluorescencia del ácido salicílico y acetil salicílico en etanol y en disoluciones de etanol-ácido sulfúrico.The rate of the descomposition of the acetylsalicylic acid in ethanolsulfuric acid mixtures has been measured by determining the liberated salicylic acid spectrophotoftuorimetricaly. The mea sures has been carried out at the temperatures of 20°, 25°, 30°, 35° and 40°C in 4% sulfuric acidethanol solution, and at 25°C in sulfuric acid-ethanol solution 1%, 2%. 4% , 8% and 12%,. The ftuorescence of salicylic acid and acetylsalicylic acid in ethanol and in ethanol-sulfuric add solutions are described