Creating and manipulating non-Abelian anyons in cold atom systems using auxiliary bosons

The possibility of realizing bosonic fractional quantum Hall effect in ultra-cold atomic systems suggests a new route to producing and manipulating anyons, by introducing auxiliary bosons of a different species that capture quasiholes and thus inherit their non-trivial braiding properties. States with localized quasiholes at any desired locations can be obtained by annihilating the auxiliary bosons at those locations. We explore how this method can be used to generate non-Abelian quasiholes of the Moore-Read Pfaffian state for bosons at filling factor $\nu=1$. We show that a Hamiltonian with an appropriate three-body interaction can produce two-quasihole states in two distinct fusion channels of the topological "qubit." Characteristics of these states that are related to the non-Abelian nature can be probed and verified by a measurement of the effective relative angular momentum of the auxiliary bosons, which is directly related to their pair distribution function. Moore-Read states of more than two quasiholes can also be produced in a similar fashion. We investigate some issues related to the experimental feasibility of this approach, in particular, how large the systems should be for a realization of this physics and to what extent this physics carries over to systems with the more standard two-body contact interaction.Comment: 16 pages, 6 figure

Flare induced penumbra formation in the sunspot of NOAA 10838

We have observed formation of penumbrae on a pore in the active region NOAA10838 using Dunn Solar Telescope at NSO,Sunpot,USA. Simultaneous observations using different instruments (DLSP,UBF,Gband and CaK) provide us with vector magnetic field at photosphere, intensity images and Doppler velocity at different heights from photosphere to chromosphere. Results from our analysis of this particular data-set suggests that penumbrae are formed as a result of relaxation of magnetic field due to a flare happening at the same time. Images in \Halpha\ show the flare (C 2.9 as per GOES) and vector magnetic fields show a re-orientation and reduction in the global $\alpha$ value (a measure of twist). We feel such relaxation of loop structures due to reconnections or flare could be one of the way by which field lines fall back to the photosphere to form penumbrae.Comment: 4 pages, Presented at IAU symposium 273- Physics of Sun and Starspot

ANTIOXIDANT AND ANTI-INFLAMMATORY PROPERTIES OF PTEROSPERMUM RUBIGINOSUM HEYNE EX WIGHT AND ARN AND PTEROSPERMUM RETICULATUM WIGHT AND ARN (STERCULIACEAE): AN IN VITRO COMPARATIVE STUDY

Objectives: Plants from the family Sterculiaceae are used as folk medicine for treating various diseases in India. This study aims to determine the antioxidant and anti-inflammatory properties of Pterospermum rubiginosum and Pterospermum reticulatum of the family Sterculiaceae. The barks of P. rubiginosum and P. reticulatum are used in traditional medicine especially in the treatment of wounds, sprains, bone fracture, etc. This study, we compare the antioxidant and anti-inflammatory potentials of the stem bark of these two plants. Methods: The free radical scavenging assays such as 2,2–diphenyl,1–picrylhydrazyl (DPPH), 2,2’–azino-bis(3-ethylbenzothiozoline-6-sulfonic acid) (ABTS), hydroxyl radical, nitric oxide radical, phosphormolybdenum assay, and reducing power assay are used for the measurement of antioxidant potentials. The in vitro anti-inflammatory activities of the extracts are evaluated by means of lipoxygenase (LOX) and protease inhibition. Results: Both P. rubiginosum and P. reticulatum scavenge DPPH (70.10% and 91.02%), ABTS (94.48 and 98.19%), hydroxy (76.02 and 87.67%), and nitric oxide (87.02 and 80.84%) radicals. Phosphomolybdenum assay and reducing power assay, used for the measurement of antioxidant potentials also showed good results. Regarding the anti-inflammatory potential, the methanolic extract of the plants shows anti-protease activity (51.29 and 64.93%) and anti-LOX activity (56%) while P. rubiginosum does not exhibit anti-LOX activity. Conclusion: The above results demonstrate that the plants P. rubiginosum and P. reticulatum are rich source of antioxidant and anti-inflammatory compounds and it is the first report on theantioxidant and anti-inflammatory properties of the barks of these plants

Search for exact local Hamiltonians for general fractional quantum Hall states

We report on our systematic attempts at finding local interactions for which the lowest-Landau-level projected composite-fermion wave functions are the unique zero energy ground states. For this purpose, we study in detail the simplest non-trivial system beyond the Laughlin states, namely bosons at filling $\nu=\frac{2}{3}$ and identify local constraints among clusters of particles in the ground state. By explicit calculation, we show that no Hamiltonian up to (and including) four particle interactions produces this state as the exact ground state, and speculate that this remains true even when interaction terms involving greater number of particles are included. Surprisingly, we can identify an interaction, which imposes an energetic penalty for a specific entangled configuration of four particles with relative angular momentum of $6\hbar$, that produces a unique zero energy solution (as we have confirmed for up to 12 particles). This state, referred to as the $\lambda$-state, is not identical to the projected composite-fermion state, but the following facts suggest that the two might be topologically equivalent: the two sates have a high overlap; they have the same root partition; the quantum numbers for their neutral excitations are identical; and the quantum numbers for the quasiparticle excitations also match. On the quasihole side, we find that even though the quantum numbers of the lowest energy states agree with the prediction from the composite-fermion theory, these states are not separated from the others by a clearly identifiable gap. This prevents us from making a conclusive claim regarding the topological equivalence of the $\lambda$ state and the composite-fermion state. Our study illustrates how new candidate states can be identified from constraining selected many particle configurations and it would be interesting to pursue their topological classification.Comment: 21 pages, 11 figure