21,043 research outputs found
Enhanced quantum teleportation in the background of Schwarzschild spacetime by weak measurements
It is commonly believed that the fidelity of quantum teleportation in the
gravitational field would be degraded due to the heat up by the Hawking
radiation. In this paper, we point out that the Hawking effect could be
eliminated by the combined action of pre- and post-weak measurements, and thus
the teleportation fidelity is almost completely protected. It is intriguing to
notice that the enhancement of fidelity could not be attributed to the
improvement of entanglement, but rather to the probabilistic nature of weak
measurements. Our work extends the ability of weak measurements as a quantum
technique to battle against gravitational decoherence in relativistic quantum
information.Comment: 9 pages, 5 figures, comments are welcom
Feature Selective Networks for Object Detection
Objects for detection usually have distinct characteristics in different
sub-regions and different aspect ratios. However, in prevalent two-stage object
detection methods, Region-of-Interest (RoI) features are extracted by RoI
pooling with little emphasis on these translation-variant feature components.
We present feature selective networks to reform the feature representations of
RoIs by exploiting their disparities among sub-regions and aspect ratios. Our
network produces the sub-region attention bank and aspect ratio attention bank
for the whole image. The RoI-based sub-region attention map and aspect ratio
attention map are selectively pooled from the banks, and then used to refine
the original RoI features for RoI classification. Equipped with a light-weight
detection subnetwork, our network gets a consistent boost in detection
performance based on general ConvNet backbones (ResNet-101, GoogLeNet and
VGG-16). Without bells and whistles, our detectors equipped with ResNet-101
achieve more than 3% mAP improvement compared to counterparts on PASCAL VOC
2007, PASCAL VOC 2012 and MS COCO datasets
Enhancing teleportation of quantum Fisher information by partial measurements
The purport of quantum teleportation is to completely transfer information
from one party to another distant partner. However, from the perspective of
parameter estimation, it is the information carried by a particular parameter,
not the information of total quantum state that needs to be teleported. Due to
the inevitable noise in environment, we propose two schemes to enhance quantum
Fisher information (QFI) teleportation under amplitude damping noise with the
technique of partial measurements. We find that post partial measurement can
greatly enhance the teleported QFI, while the combination of prior partial
measurement and post partial measurement reversal could completely eliminate
the effect of decoherence. We show that, somewhat consequentially, enhancing
QFI teleportation is more economic than that of improving fidelity
teleportation. Our work extends the ability of partial measurements as a
quantum technique to battle decoherence in quantum information processing.Comment: Revised version, minor changes, accepted by Phys. Rev.
Protecting entanglement from correlated amplitude damping channel using weak measurement and quantum measurement reversal
Based on the quantum technique of weak measurement, we propose a scheme to
protect the entanglement from correlated amplitude damping decoherence. In
contrast to the results of memoryless amplitude damping channel, we show that
the memory effects play a significant role in the suppression of entanglement
sudden death and protection of entanglement under severe decoherence. Moreover,
we find that the initial entanglement could be drastically amplified by the
combination of weak measurement and quantum measurement reversal even under the
correlated amplitude damping channel. The underlying mechanism can be
attributed to the probabilistic nature of weak measurements.Comment: 11 pages, 5 figures, accepted by Quantum Information Processin
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