747 research outputs found
Estimating the impact of ungulates on holocene steppe ecosystems by analyzing repaired injuries in land snail shells
In this study we propose a method for estimating the impact of ungulates on Holocene steppe ecosystems by analyzing repaired injuries in fossil shells of the land snail Helicopsis striata Mülle
Entanglement of macroscopically distinct states of light
Schr\"odinger's famous Gedankenexperiment has inspired multiple generations
of physicists to think about apparent paradoxes that arise when the logic of
quantum physics is applied to macroscopic objects. The development of quantum
technologies enabled us to produce physical analogues of Schr\"odinger's cats,
such as superpositions of macroscopically distinct states as well as entangled
states of microscopic and macroscopic entities. Here we take one step further
and prepare an optical state which, in Schr\"odinger's language, is equivalent
to a superposition of two cats, one of which is dead and the other alive, but
it is not known in which state each individual cat is. Specifically, the alive
and dead states are, respectively, the displaced single photon and displaced
vacuum (coherent state), with the magnitude of displacement being on a scale of
photons. These two states have significantly different photon statistics
and are therefore macroscopically distinguishable
Entangled resource for interfacing single- and dual-rail optical qubits
Today's most widely used method of encoding quantum information in optical
qubits is the dual-rail basis, often carried out through the polarisation of a
single photon. On the other hand, many stationary carriers of quantum
information - such as atoms - couple to light via the single-rail encoding in
which the qubit is encoded in the number of photons. As such, interconversion
between the two encodings is paramount in order to achieve cohesive quantum
networks. In this paper, we demonstrate this by generating an entangled
resource between the two encodings and using it to teleport a dual-rail qubit
onto its single-rail counterpart. This work completes the set of tools
necessary for the interconversion between the three primary encodings of the
qubit in the optical field: single-rail, dual-rail and continuous-variable.Comment: Published in Quantu
Loss-tolerant quantum enhanced metrology and state engineering via the reverse Hong-Ou-Mandel effect
Preparing highly entangled quantum states between remote parties is a major
challenge for quantum communications [1-8]. Particularly promising in this
context are the N00N states, which are entangled N-photon wavepackets
delocalized between two different locations, providing measurement sensitivity
limited only by the uncertainty principle [1, 10-15]. However, these states are
notoriously vulnerable to losses, making it difficult both to share them
between remote locations, and to recombine them to exploit interference
effects. Here we address this challenge by utilizing the reverse version of the
Hong-Ou-Mandel effect [16] to prepare a high-fidelity two-photon N00N state
shared between two parties connected by a lossy optical channel. Furthermore,
we demonstrate that the enhanced phase sensitivity can be directly exploited in
the two distant locations, and we remotely prepare superpositions of coherent
states, known as Schr\"odinger's cat states" [17, 18]
Analysis of microstrip structures by numerical conformal transformations technique
Computer aided microstrip structures modeling has been performed by conformal mapping technique. A new approach to reduce the connectivity order of the original cross-section geometry of the structure is proposed. The multiply connected domain
is reduced to simply connected ones by implementation of magnetic slits concept. The microstrip structures analysis is carried out by numerical conformal transformations technique realized in Schwarz–Christoffel toolbox for MATLAB. This technique is applied to the quasi-static analysis of coupled microstrip lines taking into account the conductor thickness. Described approach ensures high numerical efficiency and can be used for accurate analysis of complex microstrip structures
Assessment of the genetic distances between some species of the family Bradybaenidae (Mollusca, Pulmonata)
On the basis of inter-simple sequence repeat (ISSR) loci and the nucleotide sequences of nuclear (18S and ITS-1) and mitochondrial genes (COI and 16S), a phylogenetic analysis of the three species of terrestrial mollusks of the family Bradybaenidae (Mollusca, Pulmonata), Bradybaena fruticum Mull., Bradybaena schrencki Midd., and Bradybaena transbaicalia Shileyko, was conducted to clarify their taxonomic statu
Thermal phase transitions in rotating QCD with dynamical quarks
Relativistic rotation causes a change of QCD critical temperatures. Various
phenomenological and effective models predict a decrease of the critical
temperatures in rotating QCD. Nevertheless, lattice simulations showed that the
critical temperature in gluodynamics increases due to rotation. We extend the
lattice study to the theory with dynamical fermions. We present the first
lattice results for rotating QCD with dynamical clover-improved Wilson
quarks. We also study separately the effect of rotation on gluonic and
fermionic degrees of freedom. It is shown that separate rotations of gluons and
fermions have opposite effects on the critical temperatures. In aggregate, the
pseudo-critical temperatures in QCD increase with angular velocity. Dependence
of the results on the pion mass is also discussed.Comment: 10 pages, 5 figures, Proceedings of the 39th International Symposium
on Lattice Field Theory, 8th-13th August, 2022, Bonn, German
On the issue of the genetic structure of species found in the relic communities of central russian upland southern territories
This paper performs a comparative analysis of population genetic structure concerning specially protected species of terrestrial mollusk Helicopsis striata Müller and the herbaceous plant Androsace kozo-poljanskii Ovs
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