2,205 research outputs found
Unextendible Maximally Entangled Bases in
The construction of unextendible maximally entangled bases is tightly related
to quantum information processing like local state discrimination. We put
forward two constructions of UMEBs in () based on the constructions of UMEBs in and in , which generalizes the results in [Phys. Rev. A. 94, 052302 (2016)] by
two approaches. Two different 48-member UMEBs in have been constructed in detail
Molecular states from and interactions
In this work, we preform a systematic investigation about hidden heavy and
doubly heavy molecular states from the
and
interactions in the quasipotential
Bethe-Salpeter equation (qBSE) approach. With the help of Lagrangians with
heavy quark and chiral symmetries, interaction potentials are constructed
within the one-boson-exchange model in which we include the , ,
, and exchanges, as well as or
exchange. Possible bound states from the interactions considered are searched
for as the pole of scattering amplitude. The results suggest that
experimentally observed states, , , , and
, can be related to the , ,
, and interactions with quantum numbers
, respectively. The interaction is also
attractive enough to produce a pole with which is related to the
. Within the same theoretical frame, the existence of and
molecular states with are predicted. The possible
molecular states with and and their
bottom partners are also suggested by the calculation. In the doubly heavy
sector, no bound state is produced from the interaction
while a bound state is found with from
interaction. The interaction produces three
molecular states with , and .Comment: 7 page
Confirming the 115.5-day periodicity in the X-ray light curve of ULX NGC 5408 X-1
The Swift/XRT light curve of the ultraluminous X-ray (ULX) source NGC 5408
X-1 was re-analyzed with two new numerical approaches, Weighted Wavelet
-transform (WWZ) and CLEANest, that are different from previous studies.
Both techniques detected a prominent periodicity with a time scale of
days, in excellent agreement with the detection of the same
periodicity first reported by Strohmayer (2009). Monte Carlo simulation was
employed to test the statisiticak confidence of the 115.5-day periodicity,
yielding a statistical significance of (or ). The robust
detection of the 115.5-day quasi-periodic oscillations (QPOs), if it is due to
the orbital motion of the binary, would infer a mass of a few thousand
for the central black hole, implying an intermediate-mass black hole
in NGC 5408 X-1.Comment: 6 pages, 2 figures, submitted to Research in Astronomy and
Astrophysics (RAA
Holographic Storage of Biphoton Entanglement
Coherent and reversible storage of multi-photon entanglement with a multimode
quantum memory is essential for scalable all-optical quantum information
processing. Although single photon has been successfully stored in different
quantum systems, storage of multi-photon entanglement remains challenging
because of the critical requirement for coherent control of photonic
entanglement source, multimode quantum memory, and quantum interface between
them. Here we demonstrate a coherent and reversible storage of biphoton
Bell-type entanglement with a holographic multimode atomic-ensemble-based
quantum memory. The retrieved biphoton entanglement violates Bell's inequality
for 1 microsecond storage time and a memory-process fidelity of 98% is
demonstrated by quantum state tomography.Comment: 5 pages, 4 figures, accepted by Phys. Rev. Let
Induction- and conditioning-protocol dependent involvement of NR2B-containing NMDA receptors in synaptic potentiation and contextual fear memory in the hippocampal CA1 region of rats
Long-term potentiation (LTP) in the hippocampal CA1 region requires the activation of N-methyl-D-aspartate receptors (NMDARs). Studies using genetic and pharmacological approaches have reported inconsistent results of the requirement of NR2B-containing NMDARs in LTP in the CA1 region. Pharmacological studies showed that NR2B-containing NMDARs are not required for LTP, while genetic studies reported that over-expression of NR2B-NMDARs enhances LTP and hippocampus-dependent memory. Here, we provide evidence showing that the functional role of NR2B-NMDARs in hippocampal LTP and memory depends on LTP-inducing and behavior-conditioning protocols. Inhibition of NR2B-NMDARs with the NR2B selective antagonist ifenprodil or Ro25-6981 suppressed LTP induced by spike-timing protocol, with no impact on LTP induced by pairing protocol or two-train high-frequency stimulation (HFS) protocol. Inhibition of NR2B-NMDARs did not affect the late phase LTP induced by four-train HFS. Ca2+ imaging showed that there was difference in kinetics of intracellular Ca2+ signals induced by spiking-timing and pairing protocols. Pre-training intra-CA1 infusion of ifenprodil or Ro25-6981 impaired the contextual fear memory induced by five CS-US pairings, with no effect on the memory induced by one CS-US pairing
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