4,033 research outputs found
What can quantum optics say about computational complexity theory?
Considering the problem of sampling from the output photon-counting
probability distribution of a linear-optical network for input Gaussian states,
we obtain results that are of interest from both quantum theory and the
computational complexity theory point of view. We derive a general formula for
calculating the output probabilities, and by considering input thermal states,
we show that the output probabilities are proportional to permanents of
positive-semidefinite Hermitian matrices. It is believed that approximating
permanents of complex matrices in general is a #P-hard problem. However, we
show that these permanents can be approximated with an algorithm in BPP^NP
complexity class, as there exists an efficient classical algorithm for sampling
from the output probability distribution. We further consider input
squeezed-vacuum states and discuss the complexity of sampling from the
probability distribution at the output.Comment: 5 pages, 1 figur
Quantum teleportation with nonclassical correlated states in noninertial frames
Quantum teleportation is studied in noninertial frame, for fermionic case,
when Alice and Bob share a general nonclassical correlated state. In
noninertial frames two fidelities of teleportation are given. It is found that
the average fidelity of teleportation from a separable and nonclassical
correlated state is increasing with the amount of nonclassical correlation of
the state. However, for any particular nonclassical correlated state, the
fidelity of teleportation decreases by increasing the acceleration.Comment: 10 pages, 3 figures, expanded version to appear in Quantum Inf.
Proces
LC50 and bioaccumulation of Cd in different life stages of Artemia urmiana
This study was conducted in vitro to assess lethality, LC50 and the possibility of bioaccumulation of cadmium in various life stages of Artemia urmiana. Artemia is highly used in aquaculture; hence the response of the organisms to pollutants, such as cadmium regarding the increase in environmental pollution is of high importance. This experiment was performed in Faculty of Marine science and Technology, Islamic Azad University and Atomic Energy Organization of Iran in 2009. In the first stage, smaller than 1day naupliis were exposed to 10 different concentrations from 0 to 250mg/l Cd. LC50 of Cd in 24h of A. urmiana exposure was 189.33mg/L. Next, the accumulations of Cd in 5, 10, 15 and 20mg/l Cd were examined in 1, 5, 11 and 17 days of Artemia urmiana life. The results showed that Artemia urmiana has the ability of accumulation of cadmium and the accumulation level depends upon the concentration of the cadmium in the environment as well as different living periods of Artemia. We found that increasing the concentration of cadmium in the environment increases its accumulation in Artemia. There was a significant difference in accumulation of Cd between 5mg/l Cd (0.267ppm) and 20mg/l Cd (0.364ppm) in the first day of A. urmiana life (P<0.05). In all treatments of the 11 day Artemia, bioaccumulations of Cd increased with increasing of cadmium concentration. Maximum accumulation of Cd was in 20mg/l Cd in the 11 day Artemia. Results showed that although A.urmiana is resistant to Cd, however in 250mg/l, cadmium has significant toxic effects on Artemia survival (3.33%)
On the feasibility of attribute-based encryption on Internet of Things devices
Attribute-based encryption (ABE) could be an effective cryptographic tool for the secure management of Internet of Things (IoT) devices, but its feasibility in the IoT has been under-investigated thus far. This article explores such feasibility for well-known IoT platforms, namely, Intel Galileo Gen 2, Intel Edison, Raspberry pi 1 model B, and Raspberry pi zero, and concludes that adopting ABE in the IoT is indeed feasible
Boson Sampling from Gaussian States
We pose a generalized Boson Sampling problem. Strong evidence exists that
such a problem becomes intractable on a classical computer as a function of the
number of Bosons. We describe a quantum optical processor that can solve this
problem efficiently based on Gaussian input states, a linear optical network
and non-adaptive photon counting measurements. All the elements required to
build such a processor currently exist. The demonstration of such a device
would provide the first empirical evidence that quantum computers can indeed
outperform classical computers and could lead to applications
Single-experiment-detectable multipartite entanglement witness for ensemble quantum computing
In this paper we provide an operational method to detect multipartite
entanglement in ensemble-based quantum computing. This method is based on the
concept of entanglement witness. We decompose the entanglement witness for each
class of multipartite entanglement into nonlocal operations in addition to
local measurements. Individual single qubit measurements are performed
simultaneously, hence complete detection of entanglement is performed in a
single run experiment. This approach is particularly important for experiments
where it is operationally difficult to prepare several copies of an unknown
quantum state and in this sense the introduced scheme in this work is superior
to the generally used entanglement witnesses that require a number of
experiments and preparation of copies of quantum state.Comment: 9 pages, 5 figures, minor changes have been mad
- …