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ردیف | عنوان | نوع |
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1 |
Design of an Integrated Bell-State Analyzer on a Thin-Film Lithium Niobate Platform
طراحی یک آنالایزر حالت زنگ یکپارچه بر روی بستر نازک لیتیوم نیوبات-2022 Trapped ions are excellent candidates for quantum
computing and quantum networks because of their long coherence
times, ability to generate entangled photons as well as high fidelity
single- and two-qubit gates. To scale up trapped ion quantum
computing, we need a Bell-state analyzer on a reconfigurable platform that can herald high fidelity entanglement between ions. In
this work, we design a photonic Bell-state analyzer on a reconfigurable thin-film lithium niobate platform for polarization-encoded
qubits.We optimize the device to achieve high fidelity entanglement
between two trapped ions and find >99% fidelity. Apart from
that, the directional coupler used in our design can achieve any
polarization-independent power splitting ratio which can have a
rich variety of applications in the integrated photonic technology.
The proposed device can scale up trapped ion quantum computing
as well as other optically active spin qubits, such as color centers
in diamond, quantum dots, and rare-earth ions.
Index Terms: Bell-state analyzer | thin-film lithium niobate | scalable quantum computing | trapped ions | entanglement | polarization qubits | polarization-independent directional coupler. |
مقاله انگلیسی |
2 |
Tracking the northern seasonal cap retreat of mars using computer vision
ردیابی عقب نشینی کلاهک فصلی شمالی مریخ با استفاده از بینایی کامپیوتر-2022 Using polar stereographic images from the Mars Color Imager (MARCI), we use Python
to autonomously track the Northern Polar Seasonal Cap (NPSC) recession from Mars Years (MY)
29 to MY 35 between Ls = 10° and Ls = 70°. We outline the cap and find an ellipse of best fit. We
then compare our results to previously published recession rates, that were manually tracked,
and find them to be consistent. Our process benefits from being automated, which increases
the speed of tracking and allows us to monitor the recession with higher Ls fidelity than past
studies. We find that most MYs have a local minimum recession rate at Ls = ~32° and a local
maximum at Ls = ~51°. We also find that MY 30 experiences a rapid latitude increasing event
that involves ~1° Ls of a rapid increase and ~5° Ls of slower recession, which then increases
above the interannual average rate. We interpret this to be the result of a major sublimation
driven by off-polar winds. We also discover divergent effects in the recession and size of the
NPSC following the MY 28 and MY 35 global dust storms. MY 29’s cap is significantly smaller
and retreats slower than the multi-year average, whereas MY 35’s cap is slighter larger and
retreats very close to the average. We hypothesize that the diverging behavior of the caps in
post-storm years can be a result of the differences in the date of onset and the duration of the
storms.
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مقاله انگلیسی |
3 |
Generation of Truly Random Numbers on a Quantum Annealer
تولید اعداد واقعا تصادفی در یک آنیلر کوانتومی-2022 This study investigates how qubits of modern quantum annealers (QA) such as D-Wave can be
applied for generating truly random numbers. We show how a QA can be initialised and how the annealing
schedule can be set so that after the annealing, thousands of truly random binary numbers are measured in
parallel. Those can then be converted to uniformly distributed natural or real numbers in desired ranges,
either biased or unbiased. We discuss the observed qubits’ properties and their influence on the random
number generation and consider various physical factors that influence the performance of our generator,
i.e., digital-to-analogue quantisation errors, flux errors, temperature errors and spin bath polarisation. The
numbers generated by the proposed algorithm successfully pass various tests on randomness from the NIST
test suite. Our source code and large sets of truly random numbers will be made publicly available on our
project web page.
INDEX TERMS: Random numbers | true randomness test | superconducting flux qubits | quantum annealing | QUBO |
مقاله انگلیسی |
4 |
Natural Embedding of the Stokes Parameters of Polarimetric Synthetic Aperture Radar Images in a Gate-Based Quantum Computer
جاسازی طبیعی پارامترهای استوکس تصاویر رادار دیافراگم مصنوعی قطبی در یک کامپیوتر کوانتومی مبتنی بر گیت-2022 Quantum algorithms are designed to process quantum data (quantum bits) in a gate-based quantum computer. They
are proven rigorously that they reveal quantum advantages over
conventional algorithms when their inputs are certain quantum
data or some classical data mapped to quantum data. However,
in a practical domain, data are classical in nature, and they are
very big in dimension, size, and so on. Hence, there is a challenge
to map (embed) classical data to quantum data, and even no
quantum advantages of quantum algorithms are demonstrated
over conventional ones when one processes the mapped classical
data in a gate-based quantum computer. For the practical domain
of earth observation (EO), due to the different sensors on remotesensing platforms, we can map directly some types of EO data
to quantum data. In particular, we have polarimetric synthetic
aperture radar (PolSAR) images characterized by polarized
beams. A polarized state of the polarized beam and a quantum
bit are the Doppelganger of a physical state. We map them to
each other, and we name this direct mapping a natural embedding,
otherwise an artificial embedding. Furthermore, we process our
naturally embedded data in a gate-based quantum computer by
using a quantum algorithm regardless of its quantum advantages
over conventional techniques; namely, we use the QML network
as a quantum algorithm to prove that we naturally embedded
our data in input qubits of a gate-based quantum computer.
Therefore, we employed and directly processed PolSAR images
in a QML network. Furthermore, we designed and provided a
QML network with an additional layer of a neural network,
namely, a hybrid quantum-classical network, and demonstrate
how to program (via optimization and backpropagation) this
hybrid quantum-classical network when employing and processing PolSAR images. In this work, we used a gate-based quantum
computer offered by an IBM Quantum and a classical simulator
for a gate-based quantum computer. Our contribution is that
we provided very specific EO data with a natural embedding
feature, the Doppelganger of quantum bits, and processed them
in a hybrid quantum-classical network. More importantly, in the
future, these PolSAR data can be processed by future quantum
algorithms and future quantum computing platforms to obtain
(or demonstrate) some quantum advantages over conventional
techniques for EO problems.
Index Terms: Natural embedding | parameterized quantum circuit | polarimetric synthetic aperture radar (PolSAR) | quantum machine learning (QML). |
مقاله انگلیسی |
5 |
Polarization-Based Quantum Key Distribution Encoder and Decoder on Silicon Photonics
رمزگذار و رمزگشای توزیع کلید کوانتومی مبتنی بر پلاریزاسیون در فوتونیک سیلیکون-2022 Private and secure communication is an indispensable
part of the government and individual activities. With the everevolving large-scale of quantum computing, traditional public-key
cryptography is severely threatened since its security only relies
on the computational complexity of certain mathematical functions. Quantum key distribution (QKD), ascribed to its security
based on the inviolability of physics laws, provides an absolutely
information-secure solution for the future extensive communication encrypting. Herein this Letter, we proposed a simplified and
reconfigurable silicon photonics encoder using a pass-block architecture and experimentally demonstrated its performance with a
specialized silicon photonics decoder for high-speed quantum key
distribution in polarization-based decoy-state BB84 protocol. We
achieved an estimated asymptotic secret key rate of 868 kbps with
measured quantum bit error rate (QBER) of 0.90% (Z base) and
1.34% (X base) over 20 km emulated fiber link. This work further
advances the process of applying QKD using silicon photonics
devices into the future secure telecommunication network.
Index Terms: Quantum key distribution (QKD) | silicon photonics. |
مقاله انگلیسی |
6 |
Polar Codes for Quantum Reading
کدهای قطبی برای خواندن کوانتومی-2022 Quantum readout provides a general framework
for formulating statistical discrimination of quantum channels.
Several paths have been taken for such this problem. However,
there is much to be done in the avenue of optimizing channel
discrimination using classical codes. At least two open questions
can be pointed out: how to construct low complexity encoding
schemes that are interesting for channel discrimination and,
more importantly, how to develop capacity-achieving protocols.
This paper aims at presenting a solution to these questions
using polar codes. Firstly, we characterize the information rate
and reliability parameter of the channels under polar encoding.
We also show that the error probability of the scheme proposed
decays exponentially with the square root of the code length.
Secondly, an analysis of the optimal quantum states to be used
as probes is given. keywords: Quantum reading | polar codes | capacity achieving protocols. |
مقاله انگلیسی |
7 |
Cost-Effective ML-Powered Polarization-Encoded Quantum Key Distribution
توزیع کلید کوانتومی کدگذاری شده با قطبش ML مقرون به صرفه-2022 Secure communications have become a requirement
for virtually all kind of applications. Currently, two distant parties can generate shared random secret keys by using public key
cryptography. However, quantum computing represents one of the
greatest threats for the finite complexity of the mathematics behind
public key cryptography. In contrast, Quantum Key Distribution
(QKD) relies on properties of quantum mechanics, which enables
eavesdropping detection and guarantees the security of the key.
Among QKD systems, polarization encoded QKD has been successfully tested in laboratory experiments and recently demonstrated
in closed environments. The main drawback of QKD is its high
cost, which comes, among others, from: i) the requirements for the
quantum transmitters and receivers; and ii) the need of carefully
selecting the fibers supporting the quantum channel to minimize
the environmental effects that could dramatically change the polarization state of photons. In this paper, we propose a Machine
Learning(ML)-based polarization tracking and compensation that
is able to keep shared secret key exchange to high rates even under
large fiber stressing events. Exhaustive results using both synthetic
and experimental data show remarkable performance, which can
simplify the design of both quantum transmitter and receiver, as
well as enable the use of aerial optical cables, thus reducing total
QKD system cost.
Index Terms— Machine learning | polarization-encoded quantum key distribution. |
مقاله انگلیسی |
8 |
Total fractional-order variation regularization based image reconstruction method for capacitively coupled electrical resistance tomography
روش بازسازی تصویر مبتنی بر تنظیم تغییرات مرتبه کسری کل برای توموگرافی مقاومت الکتریکی جفت شده خازنی-2021 Compared with electrical resistance tomography, capacitively coupled electrical resistance tomography (CCERT)
is preferred since it avoids problems of electrode corrosion and electrode polarization. However, reconstruction
of conductivity distribution is still a great challenge for CCERT. To improve reconstruction quality, this work
proposes a novel image reconstruction method based on total fractional-order variation regularization. Simulation work is conducted and reconstruction of several typical models is studied. Robustness of the proposed
method to noise is also conducted. Additionally, the performance of the proposed reconstruction method is
quantitatively evaluated. We have also carried out phantom experiment to further verify the effectiveness of the
proposed method. The results demonstrate that the quality of reconstruction has been largely improved when
compared with the images reconstructed by Land weber, Newton-Raphson and Tikhonov methods. The inclusion
is more accurately reconstructed and the background is much clearer even under the impact of noise.
Keywords: Capacitively coupled electrical resistance | tomography | Image reconstruction | Total fractional-order variation regularization |
مقاله انگلیسی |
9 |
Defect-engineering-enhanced electrical manipulation of anisotropic excitons in two-dimensional ReS2
دستکاری الکتریکی اکسیتون های ناهمسانگرد با نقص مهندسی در ReS2 دو بعدی-2021 Engineering the photoluminescence (PL) properties, such as emission peaks, intensity, and lifetime, is highly
desirable for widespread applications. Electric control is a facile and feasible method, and electrical manipulation
of the PL properties with a high efficiency becomes increasingly important. ReS2 has excellent environmental
stability, distinctive interlayer decoupling, and strong anisotropic properties. Herein, taking ReS2 as a prototype
material, we propose a novel strategy to enhance electrical control of anisotropic excitons in ReS2 by defect
engineering. Sulfur vacancies have been introduced controllably by mild argon plasma treatment, and contribute
to the anisotropic defect-related exciton emission whose polarization direction is almost the same as those of the
excitons along the Re–S atomic chains. However, the conversion from the neutral excitons to the defect-related
excitons significantly modulate the radiation recombination behavior under a lateral electric field. The defect engineering-enhanced electrical manipulation of anisotropic excitons paves the way towards an exciton engineering in new 2D electronic and optoelectronic devices.
Keywords: Photoluminescence | Anisotropic | Defect engineering | Electric control |
مقاله انگلیسی |
10 |
An analysis of Twitter users’ long term political view migration using cross-account data mining
تجزیه و تحلیل از مهاجرت دیدگاه های طولانی مدت کاربران توییتر با استفاده از داده های متقابل حسابداری-2021 During the 2016 US presidential election, we witnessed a polarized population and an election outcome that
defied the predictions of many media sources. In this study, we conducted a follow-up on political view
migration through tracking Twitter users’ account activity. The study was conducted by following a set of
Twitter users over a four year period. Each year, Twitter user activities were collected and analyzed by our
novel cross-account data mining algorithm. This algorithm through multiple iterations computes a numerical
political score for each user based on their connection to other users and hashtags. We identified a set of
seed users and hashtags using prominent political figures and movements to bootstrap the algorithm. The
political score distribution demonstrates a divided population on political views. We also observed that users
are more moderate in years close to elections (2017 and 2020) compared to years of none election (2018
and 2019). There is an overall migration trend from conservatives to progressives during the four years. This
change in scores across the four year time frame suggests a unique political cycle exclusive to Donald Trump’s
unprecedented presidential term. Our results in a broad sense portray the potential capabilities of a data
collection and scoring algorithm that detected a noticeable political migration and describes the broad social
characteristics of certain politically aligned users on social media platforms.
keywords: شبکه های اجتماعی | سیاست | توییتر | داده کاوی | Social networks | Politics | Twitter | Datamining |
مقاله انگلیسی |