24,147 research outputs found
8x8 Reconfigurable quantum photonic processor based on silicon nitride waveguides
The development of large-scale optical quantum information processing
circuits ground on the stability and reconfigurability enabled by integrated
photonics. We demonstrate a reconfigurable 8x8 integrated linear optical
network based on silicon nitride waveguides for quantum information processing.
Our processor implements a novel optical architecture enabling any arbitrary
linear transformation and constitutes the largest programmable circuit reported
so far on this platform. We validate a variety of photonic quantum information
processing primitives, in the form of Hong-Ou-Mandel interference, bosonic
coalescence/anticoalescence and high-dimensional single-photon quantum gates.
We achieve fidelities that clearly demonstrate the promising future for
large-scale photonic quantum information processing using low-loss silicon
nitride.Comment: Added supplementary materials, extended introduction, new figures,
results unchange
A Lightweight McEliece Cryptosystem Co-processor Design
Due to the rapid advances in the development of quantum computers and their
susceptibility to errors, there is a renewed interest in error correction
algorithms. In particular, error correcting code-based cryptosystems have
reemerged as a highly desirable coding technique. This is due to the fact that
most classical asymmetric cryptosystems will fail in the quantum computing era.
Quantum computers can solve many of the integer factorization and discrete
logarithm problems efficiently. However, code-based cryptosystems are still
secure against quantum computers, since the decoding of linear codes remains as
NP-hard even on these computing systems. One such cryptosystem is the McEliece
code-based cryptosystem. The original McEliece code-based cryptosystem uses
binary Goppa code, which is known for its good code rate and error correction
capability. However, its key generation and decoding procedures have a high
computation complexity. In this work we propose a design and hardware
implementation of an public-key encryption and decryption co-processor based on
a new variant of McEliece system. This co-processor takes the advantage of the
non-binary Orthogonal Latin Square Codes to achieve much smaller computation
complexity, hardware cost, and the key size.Comment: 2019 Boston Area Architecture Workshop (BARC'19
Superconducting Quantum Computing: A Review
Over the last two decades, tremendous advances have been made for
constructing large-scale quantum computers. In particular, the quantum
processor architecture based on superconducting qubits has become the leading
candidate for scalable quantum computing platform, and the milestone of
demonstrating quantum supremacy was first achieved using 53 superconducting
qubits in 2019. In this work, we provide a brief review on the experimental
efforts towards building a large-scale superconducting quantum computer,
including qubit design, quantum control, readout techniques, and the
implementations of error correction and quantum algorithms. Besides the state
of the art, we finally discuss future perspectives, and which we hope will
motivate further research.Comment: Updated version, Typos corrected, New references added, New
discussions adde
On the Quantum Performance Evaluation of Two Distributed Quantum Architectures
Distributed quantum applications impose requirements on the quality of the
quantum states that they consume. When analyzing architecture implementations
of quantum hardware, characterizing this quality forms an important factor in
understanding their performance. Fundamental characteristics of quantum
hardware lead to inherent tradeoffs between the quality of states and
traditional performance metrics such as throughput. Furthermore, any real-world
implementation of quantum hardware exhibits time-dependent noise that degrades
the quality of quantum states over time. Here, we study the performance of two
possible architectures for interfacing a quantum processor with a quantum
network. The first corresponds to the current experimental state of the art in
which the same device functions both as a processor and a network device. The
second corresponds to a future architecture that separates these two functions
over two distinct devices. We model these architectures as Markov chains and
compare their quality of executing quantum operations and producing entangled
quantum states as functions of their memory lifetimes, as well as the time that
it takes to perform various operations within each architecture. As an
illustrative example, we apply our analysis to architectures based on
Nitrogen-Vacancy centers in diamond, where we find that for present-day device
parameters one architecture is more suited to computation-heavy applications,
and the other for network-heavy ones. Besides the detailed study of these
architectures, a novel contribution of our work are several formulas that
connect an understanding of waiting time distributions to the decay of quantum
quality over time for the most common noise models employed in quantum
technologies. This provides a valuable new tool for performance evaluation
experts, and its applications extend beyond the two architectures studied in
this work
Constructing 2D and 3D cluster states with photonic modules
Large scale quantum information processing (QIP) and distributed quantum
computation require the ability to perform entangling operations on a large
number of qubits. We describe a new photonic module which prepares,
deterministically, photonic cluster states using an atom in a cavity as an
ancilla. Based on this module we design a network for constructing 2D cluster
states and then we extend the architecture to 3D topological cluster states.
Advantages of our design include a passive switching mechanism and the
possibility of using global control pulses for the atoms in the cavity. The
architecture described here is well suited for integrated photonic circuits on
a chip and could be used as a basis of a future quantum optical processor or in
a quantum repeater node
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