3,337 research outputs found
Topological Quantum Computing with p-Wave Superfluid Vortices
It is shown that Majorana fermions trapped in three vortices in a p-wave
superfluid form a qubit in a topological quantum computing (TQC). Several
similar ideas have already been proposed: Ivanov [Phys. Rev. Lett. {\bf 86},
268 (2001)] and Zhang {\it et al.} [Phys. Rev. Lett. {\bf 99}, 220502 (2007)]
have proposed schemes in which a qubit is implemented with two and four
Majorana fermions, respectively, where a qubit operation is performed by
exchanging the positions of Majorana fermions. The set of gates thus obtained
is a discrete subset of the relevant unitary group. We propose, in this paper,
a new scheme, where three Majorana fermions form a qubit. We show that
continuous 1-qubit gate operations are possible by exchanging the positions of
Majorana fermions complemented with dynamical phase change. 2-qubit gates are
realized through the use of the coupling between Majorana fermions of different
qubits.Comment: 5 pages, 2 figures. Two-qubit gate implementation is added
Effective field theory for spinor dipolar Bose Einstein condensates
We show that the effective theory of long wavelength low energy behavior of a
dipolar Bose-Einstein condensate(BEC) with large dipole moments (treated as a
classical spin) can be modeled using an extended Non-linear sigma model (NLSM)
like energy functional with an additional non-local term that represents long
ranged anisotropic dipole-dipole interaction. Minimizing this effective energy
functional we calculate the density and spin-profile of the dipolar
Bose-Einstein condensate in the mean-field regime for various trapping
geometries. The resulting configurations show strong intertwining between the
spin and mass density of the condensate, transfer between spin and orbital
angular momentum in the form of Einstein-de Hass effect, and novel topological
properties. We have also described the theoretical framework in which the
collective excitations around these mean field solutions can be studied and
discuss some examples qualitatively.Comment: Latex + 3 eps figures, accepted for publication in a special issue of
EPJB on "Novel Quantum Phases and Mesoscopic Physics in Quantum Gases
Topological Structure of a Vortex in Fulde-Ferrell-Larkin-Ovchinnikov State
We find theoretically that the vortex core in the
Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state is quite different from the
ordinary core by a simple topological reason. The intersection point of a
vortex and nodal plane of the FFLO state empties the excess spins. This leads
to observable consequences in the spatial structure of the spontaneous
magnetization. We analyze this topological structure based on the low lying
excitation spectrum by solving microscopic Bogoliubov-de Gennes equation to
clarify its physical origin.Comment: 4 pages, 4 figure
Majorana bound state in rotating superfluid 3He-A between parallel plates
A concrete and experimentally feasible example for testing the putative
Majorana zero energy state bound in a vortex is theoretically proposed for a
parallel plate geometry of superfluid He-A phase. We examine the
experimental setup in connection with ongoing rotating cryostat experiments.
The theoretical analysis is based on the well-established Ginzburg--Landau
functional, supplemented by microscopic calculations of the Bogoliubov--de
Gennes equation, both of which allow the precise location of the parameter
regions of the Majorana state to be found in realistic situations.Comment: 5 pages, 4 figure
Lateral distribution of electrons of air showers
The lateral distribution of electrons (LDE) of the air showers of size 10 to the 5th power to 10 to the 6th power was studied within one MU. It was found that the LDE of the air showers observed is well represented by NKG function except for vicinity of the core. It was also found that LDE measured by thin scintillators does not differ from that measured by thick ones of 50mm thickness
E1-Like Activating Enzyme Atg7 Is Preferentially Sequestered into p62 Aggregates via Its Interaction with LC3-I
p62 is constitutively degraded by autophagy via its interaction with LC3. However, the interaction of p62 with LC3 species in the context of the LC3 lipidation process is not specified. Further, the p62-mediated protein aggregation's effect on autophagy is unclear. We systemically analyzed the interactions of p62 with all known Atg proteins involved in LC3 lipidation. We find that p62 does not interact with LC3 at the stages when it is being processed by Atg4B or when it is complexed or conjugated with Atg3. p62 does interact with LC3-I and LC3-I:Atg7 complex and is preferentially recruited by LC3-II species under autophagic stimulation. Given that Atg4B, Atg3 and LC3-Atg3 are indispensable for LC3-II conversion, our study reveals a protective mechanism for Atg4B, Atg3 and LC3-Atg3 conjugate from being inappropriately sequestered into p62 aggregates. Our findings imply that p62 could potentially impair autophagy by negatively affecting LC3 lipidation and contribute to the development of protein aggregate diseases. © 2013 Gao et al
Transition effect of air shower particles in plastic scintillators
The transition effect of air shower particles in the plastic scintillators near the core was measured by scintillators of various thickness. The air showers selected for the measurement were of 10,000. Results obtained are as follows: (1) the multiplication of shower particles in the scintillators is less than 20% for that of 50 mm thickness; (2) dependence of the transition effect on age parameter is not recognized within the experimental errors
Character of energy flow in air shower core
Energy per charged particle near the core of air showers was measured by 9 energy flow detectors, which were the combination of Cerenkov counters and scintillators. Energy per particle of each detector was normalized to energy at 2m from the core. The following results were obtained as to the energy flow: (1) integral frequency distribution of mean energy per particle (averaged over 9 detectors) is composed of two groups separated distinctly; and (2) showers contained in one group show an anisotropy of arrival direction
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