با سلام خدمت کاربران در صورتی که با خطای سیستم پرداخت بانکی مواجه شدید از طریق کارت به کارت (6037997535328901 بانک ملی ناصر خنجری ) مقاله خود را دریافت کنید (تا مشکل رفع گردد).
ردیف | عنوان | نوع |
---|---|---|
1 |
Deployment-Ready Quantum Key Distribution Over a Classical Network Infrastructure in Padua
توزیع کلید کوانتومی آماده استقرار بر روی یک زیرساخت شبکه کلاسیک در پادوآ-2022 Current technological progress is driving Quantum
Key Distribution towards a commercial and worldwide scale
expansion. Its capability to deliver secure communication
regardless of the computational power of the attackers will be a
fundamental feature in the next generations of telecommunication
networks. Nevertheless, demonstrations of QKD implementation in a real operating scenario and their coexistence with the
classical telecom infrastructure are of fundamental importance
for reliable exploitation. Here we present a Quantum Key
Distribution application implemented over a classical fiber-based
infrastructure. We exploit a 50 MHz source at 1550 nm, a single 13
km-long fiber cable for both the quantum and the classical channel,
and a simplified receiver scheme with just one single-photon
detector. In this way, we achieve an error rate of approximately
2% and a secret key rate of about 1.7 kbps, thus demonstrating the
feasibility of low-cost and ready-to-use Quantum Key Distribution
systems compatible with standard classical infrastructure.
Index Terms: Classical channel | cryptography | fiber, FPGA | padua | POGNAC | quantum communication | quantum key distribution | qubit4sync | telecommunication. |
مقاله انگلیسی |
2 |
Layer VQE: A Variational Approach for Combinatorial Optimization on Noisy Quantum Computers
لایه VQE: یک رویکرد متغیر برای بهینه سازی ترکیبی در کامپیوترهای کوانتومی پر سر و صدا-2022 Combinatorial optimization on near-term quantum devices is a promising path to demonstrating quantum advantage. However, the capabilities of these devices are constrained by high noise or
error rates. In this article, inspired by the variational quantum eigensolver (VQE), we propose an iterative
layer VQE (L-VQE) approach. We present a large-scale numerical study, simulating circuits with up to
40 qubits and 352 parameters, that demonstrates the potential of the proposed approach. We evaluate
quantum optimization heuristics on the problem of detecting multiple communities in networks, for which we
introduce a novel qubit-frugal formulation. We numerically compare L-VQE with the quantum approximate
optimization algorithm (QAOA) and demonstrate that QAOA achieves lower approximation ratios while
requiring significantly deeper circuits. We show that L-VQE is more robust to finite sampling errors and has
a higher chance of finding the solution as compared with standard VQE approaches. Our simulation results
show that L-VQE performs well under realistic hardware noise.
INDEX TERMS: Combinatorial optimization | hybrid quantum-classical algorithm | quantum optimization. |
مقاله انگلیسی |
3 |
Memristor Crossbar Arrays Performing Quantum Algorithms
آرایه های ضربدری ممریستور که الگوریتم های کوانتومی را انجام می دهند-2022 There is a growing interest in quantum computers
and quantum algorithm development. It has been proved that
ideal quantum computers, with zero error rates and large
decoherence times, can solve problems that are intractable
for today’s classical computers. Quantum computers use two
resources, superposition and entanglement, that have no classical
analog. Since quantum computer platforms that are currently
available comprise only a few dozen of qubits, the use of quantum
simulators is essential in developing and testing new quantum
algorithms. We present a novel quantum simulator based on
memristor crossbar circuits and use them to simulate well-known
quantum algorithms, namely the Deutsch and Grover quantum algorithms. In quantum computing the dominant algebraic
operations are matrix-vector multiplications. The execution time
grows exponentially with the simulated number of qubits, causing
an exponential slowdown in quantum algorithm execution using
classical computers. In this work, we show that the inherent
characteristics of memristor arrays can be used to overcome this
problem and that memristor arrays can be used not only as independent quantum simulators but also as a part of a quantum computer stack where classical computers accelerators are
connected. Our memristive crossbar circuits are re-configurable
and can be programmed to simulate any quantum algorithm.
Index Terms— Memristors | memristor crossbars | quantum algorithms | quantum simulators. |
مقاله انگلیسی |
4 |
On the Logical Error Rate of Sparse Quantum Codes
در مورد میزان خطای منطقی کدهای کوانتومی پراکنده-2022 The quantum paradigm presents a phenomenon known as degeneracy that can potentially
improve the performance of quantum error correcting codes. However, the effects of this mechanism are
sometimes ignored when evaluating the performance of sparse quantum codes and the logical error rate is
not always correctly reported. In this article, we discuss previously existing methods to compute the logical
error rate and we present an efficient coset-based method inspired by classical coding strategies to estimate
degenerate errors and distinguish them from logical errors. Additionally, we show that the proposed method
presents a computational advantage for the family of Calderbank–Shor–Steane codes. We use this method
to prove that degenerate errors are frequent in a specific family of sparse quantum codes, which stresses
the importance of accurately reporting their performance. Our results also reveal that the modified decoding
strategies proposed in the literature are an important tool to improve the performance of sparse quantum
codes.
INDEX TERMS: Iterative decoding | quantum error correction (QEC) | quantum low density generator matrix codes | quantum low-density parity check (QLDPC) codes. |
مقاله انگلیسی |
5 |
Pauli Error Propagation-Based Gate Rescheduling for Quantum Circuit Error Mitigation
برنامه ریزی مجدد گیت مبتنی بر انتشار خطا پاولی برای کاهش خطای مدار کوانتومی-2022 Noisy intermediate-scale quantum algorithms, which run on noisy quantum computers, should
be carefully designed to boost the output state fidelity. While several compilation approaches have been
proposed to minimize circuit errors, they often omit the detailed circuit structure information that does
not affect the circuit depth or the gate count. In the presence of spatial variation in the error rate of the
quantum gates, adjusting the circuit structure can play a major role in mitigating errors. In this article, we
exploit the freedom of gate reordering based on the commutation rules to show the impact of gate error
propagation paths on the output state fidelity of the quantum circuit, propose advanced predictive techniques
to project the success rate of the circuit, and develop a new compilation phase postquantum circuit mapping
to improve its reliability. Our proposed approaches have been validated using a variety of quantum circuits
with different success metrics, which are executed on IBM quantum computers. Our results show that
rescheduling quantum gates based on their error propagation paths can significantly improve the fidelity
of the quantum circuit in the presence of variable gate error rates.
INDEX TERMS: Commutation rules | error propagation | gate rescheduling | noisy intermediate-scale quantum (NISQ) computer | Pauli errors | quantum circuit | quantum circuit mapping | reliability. |
مقاله انگلیسی |
6 |
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 |
7 |
Quantum Approximate Optimization Algorithm Based Maximum Likelihood Detection
الگوریتم بهینه سازی تقریبی کوانتومی مبتنی بر تشخیص حداکثر احتمال-2022 Recent advances in quantum technologies pave the
way for noisy intermediate-scale quantum (NISQ) devices, where
the quantum approximation optimization algorithm (QAOA)
constitutes a promising candidate for demonstrating tangible
quantum advantages based on NISQ devices. In this paper,
we consider the maximum likelihood (ML) detection problem of
binary symbols transmitted over a multiple-input and multipleoutput (MIMO) channel, where finding the optimal solution is
exponentially hard using classical computers. Here, we apply the
QAOA for the ML detection by encoding the problem of interest
into a level-p QAOA circuit having 2p variational parameters,
which can be optimized by classical optimizers. This level-p
QAOA circuit is constructed by applying the prepared Hamiltonian to our problem and the initial Hamiltonian alternately
in p consecutive rounds. More explicitly, we first encode the
optimal solution of the ML detection problem into the ground
state of a problem Hamiltonian. Using the quantum adiabatic
evolution technique, we provide both analytical and numerical
results for characterizing the evolution of the eigenvalues of
the quantum system used for ML detection. Then, for level-
1 QAOA circuits, we derive the analytical expressions of the
expectation values of the QAOA and discuss the complexity
of the QAOA based ML detector. Explicitly, we evaluate the
computational complexity of the classical optimizer used and the
storage requirement of simulating the QAOA. Finally, we evaluate
the bit error rate (BER) of the QAOA based ML detector and
compare it both to the classical ML detector and to the classical
minimum mean squared error (MMSE) detector, demonstrating
that the QAOA based ML detector is capable of approaching the
performance of the classical ML detector.
Index Terms: Quantum technology | maximum likelihood (ML) detection | quantum approximation optimization algorithm (QAOA) | bit error rate (BER). |
مقاله انگلیسی |
8 |
Quantum Error Correction at the Threshold: If technologists dont get beyond it, quantum computers will never be big
تصحیح خطای کوانتومی در آستانه: اگر تکنولوژیست ها از آن فراتر نروند، کامپیوترهای کوانتومی هرگز بزرگ نخواهند شد-2022 Dates chIseleD into an
ancient tombstone have more
in common with the data in
your phone or laptop than you may
realize. They both involve conventional,
classical information, carried by hardware that is relatively immune to errors.
The situation inside a quantum computer
is far different: The information itself has
its own idiosyncratic properties, and
compared with standard digital
microelectronics, state-of-the-art
quantum-computer hardware is more
than a billion trillion times as likely to
suffer a fault. This tremendous susceptibility to errors is the single biggest problem holding back quantum computing
from realizing its great promise.
Fortunately, an approach known as
quantum error correction (QEC) can
remedy this problem, at least in principle. A mature body of theory built up
over the past quarter century now provides a solid theoretical foundation, and
experimentalists have demonstrated
dozens of proof-of-principle examples
of QEC. But these experiments still have
not reached the level of quality and
sophistication needed to reduce the
overall error rate in a system.
keywords: |
مقاله انگلیسی |
9 |
Timing and Resource-Aware Mapping of Quantum Circuits to Superconducting Processors
نگاشت زمان بندی و آگاهی از منابع مدارهای کوانتومی به پردازنده های ابررسانا-2022 Quantum algorithms need to be compiled to respect
the constraints imposed by quantum processors, which is known
as the mapping problem. The mapping procedure will result in an
increase of the number of gates and of the circuit latency, decreasing the algorithm’s success rate. It is crucial to minimize mapping
overhead, especially for noisy intermediate-scale quantum (NISQ)
processors that have relatively short qubit coherence times and
high gate error rates. Most of prior mapping algorithms have only
considered constraints, such as the primitive gate set and qubit
connectivity, but the actual gate duration and the restrictions
imposed by the use of shared classical control electronics have
not been taken into account. In this article, we present a mapper
called Qmap to make quantum circuits executable on scalable
processors with the objective of achieving the shortest circuit
latency. In particular, we propose an approach to formulate the
classical control restrictions as resource constraints in a conventional list scheduler with polynomial complexity. Furthermore,
we implement a routing heuristic to cope with the connectivity limitation. This router finds a set of movement operations
that minimally extends circuit latency. To analyze the mapping
overhead and evaluate the performance of different mappers, we
map 56 quantum benchmarks onto a superconducting processor named Surface-17. Compared to a prior mapping strategy
that minimizes the number of operations, Qmap can reduce the
latency overhead (LtyOH) up to 47.3% and operation overhead
up to 28.6%, respectively.
Index Terms—Quantum compilation | quantum computing | resource-constrained scheduling | routing. |
مقاله انگلیسی |
10 |
Toward a Union-Find Decoder for Quantum LDPC Codes
به سمت رمزگشای Union-Find برای کدهای LDPC کوانتومی-2022 Quantum LDPC codes are a promising direction
for low overhead quantum computing. In this paper, we propose
a generalization of the Union-Find decoder as a decoder for
quantum LDPC codes. We prove that this decoder corrects all
errors with weight up to Anα for some A, α > 0, where
n is the code length, for different classes of quantum LDPC
codes such as toric codes and hyperbolic codes in any dimension
D ≥ 3 and quantum expander codes. To prove this result,
we introduce a notion of covering radius which measures the
spread of an error from its syndrome. We believe this notion
could find application beyond the decoding problem. We also
perform numerical simulations, which show that our Union-Find
decoder outperforms the belief propagation decoder in the low
error rate regime in the case of a quantum LDPC code with
length 3600.
keywords: Quantum computing | error correction | decoding. |
مقاله انگلیسی |