scholarly journals Exact and approximate continuous-variable gate decompositions

Quantum ◽  
2021 ◽  
Vol 5 ◽  
pp. 394
Author(s):  
Timjan Kalajdzievski ◽  
Nicolás Quesada
Keyword(s):  
Decomposition Methods ◽  
Continuous Variable ◽  
Quantum Computers ◽  
Decomposition Techniques ◽  
New Techniques ◽  
Circuit Depth ◽  
Continuous Variable Operations

We gather and examine in detail gate decomposition techniques for continuous-variable quantum computers and also introduce some new techniques which expand on these methods. Both exact and approximate decomposition methods are studied and gate counts are compared for some common operations. While each having distinct advantages, we find that exact decompositions have lower gate counts whereas approximate techniques can cover decompositions for all continuous-variable operations but require significant circuit depth for a modest precision.

scholarly journals Decomposition and gluing for adiabatic quantum optimization

2014 ◽  
Vol 14 (11&12) ◽  
pp. 949-965
Author(s):  
Micah Blake McCurdy ◽  
Jeffrey Egger ◽  
Jordan Kyriakidis
Keyword(s):  
Numerical Results ◽  
Quantum Computers ◽  
Integer Factorization ◽  
Foreseeable Future ◽  
Decomposition Techniques ◽  
Np Problems ◽  
Quantum Optimization

Farhi and others~\cite{Farhi} have introduced the notion of solving NP problems using adiabatic quantum computers. We discuss an application of this idea to the problem of integer factorization, together with a technique we call \emph{gluing} which can be used to build adiabatic models of interesting problems. Although adiabatic quantum computers already exist, they are likely to be too small to directly tackle problems of interesting practical sizes for the foreseeable future. Therefore, we discuss techniques for decomposition of large problems, which permits us to fully exploit such hardware as may be available. Numerical results suggest that even simple decomposition techniques may yield acceptable results with subexponential overhead, independent of the performance of the underlying device.

Circuit depth reduction algorithm for QUBO and Ising models in gate-model quantum computers

2021 ◽  
Author(s):  
Sun Woo Park ◽  
Hyunju Lee ◽  
Byung Chun Kim ◽  
Youngho Woo ◽  
Kyungtaek Jun
Keyword(s):  
Ising Models ◽  
Quantum Computers ◽  
Reduction Algorithm ◽  
Circuit Depth ◽  
Depth Reduction

scholarly journals Strawberry Fields: A Software Platform for Photonic Quantum Computing

Quantum ◽  
2019 ◽  
Vol 3 ◽  
pp. 129 ◽  
Author(s):  
Nathan Killoran ◽  
Josh Izaac ◽  
Nicolás Quesada ◽  
Ville Bergholm ◽  
Matthew Amy ◽  
...  
Keyword(s):  
Quantum Computer ◽  
Quantum Circuit ◽  
Continuous Variable ◽  
Quantum Computers ◽  
Circuit Optimization ◽  
Hamiltonian Simulation ◽  
Quantum Programming ◽  
Quantum Polynomial ◽  
Main Components ◽  
Near Future

We introduce Strawberry Fields, an open-source quantum programming architecture for light-based quantum computers, and detail its key features. Built in Python, Strawberry Fields is a full-stack library for design, simulation, optimization, and quantum machine learning of continuous-variable circuits. The platform consists of three main components: (i) an API for quantum programming based on an easy-to-use language named Blackbird; (ii) a suite of three virtual quantum computer backends, built in NumPy and TensorFlow, each targeting specialized uses; and (iii) an engine which can compile Blackbird programs on various backends, including the three built-in simulators, and - in the near future - photonic quantum information processors. The library also contains examples of several paradigmatic algorithms, including teleportation, (Gaussian) boson sampling, instantaneous quantum polynomial, Hamiltonian simulation, and variational quantum circuit optimization.

scholarly journals Unsupervised event classification with graphs on classical and photonic quantum computers

2021 ◽  
Vol 2021 (8) ◽  
Author(s):  
Andrew Blance ◽  
Michael Spannowsky
Keyword(s):  
Anomaly Detection ◽  
Clustering Algorithm ◽  
High Energy ◽  
New Physics ◽  
Continuous Variable ◽  
Quantum Computers ◽  
Detection Model ◽  
Novel Method ◽  
Formula Complexity ◽  
Boson Sampling

Abstract Photonic Quantum Computers provide several benefits over the discrete qubit-based paradigm of quantum computing. By using the power of continuous-variable computing we build an anomaly detection model to use on searches for New Physics. Our model uses Gaussian Boson Sampling, a #P-hard problem and thus not efficiently accessible to classical devices. This is used to create feature vectors from graph data, a natural format for representing data of high-energy collision events. A simple K-means clustering algorithm is used to provide a baseline method of classification. We then present a novel method of anomaly detection, combining the use of Gaussian Boson Sampling and a quantum extension to K-means known as Q-means. This is found to give equivalent results compared to the classical clustering version while also reducing the $$ \mathcal{O} $$ O complexity, with respect to the sample’s feature-vector length, from $$ \mathcal{O}(N) $$ O N to $$ \mathcal{O}\left(\log (N)\right) $$ O log N .

A Method to Improve Quantum State Fidelity in Circuits Executed on IBM’s Quantum Computers

2021 ◽  
Author(s):  
Mitali Sisodia ◽  
Abhishek Shukla ◽  
Alexandre A. A. de Almeida ◽  
Gerhard W. Dueck ◽  
Anirban Pathak
Keyword(s):  
Quantum Computing ◽  
Quantum State ◽  
Classical Limit ◽  
The State ◽  
Present Approach ◽  
Quantum Computers ◽  
Output State ◽  
Circuit Depth

Recently, various quantum computing and communication tasks have been implemented using IBM's superconductivity-based quantum computers. Here, we show that the circuits used in most of those works were not optimized, and obtain the corresponding optimized circuits. Optimized circuits implementable in IBM quantum computers are also obtained for a set of reversible benchmark circuits. With a clear example, it is shown that the reduction in circuit cost enhances the fidelity of the output state (with respect to the theoretically expected state in the absence of noise) as lesser number of gates and circuit depth introduce lesser amount of errors during evolution of the state. Further, considering Mermin inequality as an example, it is shown that the violation of classical limit is enhanced when we use optimized circuits. Thus, the present approach can be used to identify relatively weaker signature of quantumness and to establish quantum supremacy in a stronger manner.

scholarly journals Efficient verification of Boson Sampling

Quantum ◽  
2021 ◽  
Vol 5 ◽  
pp. 578
Author(s):  
Ulysse Chabaud ◽  
Frédéric Grosshans ◽  
Elham Kashefi ◽  
Damian Markham
Keyword(s):  
Large Class ◽  
Single Mode ◽  
Continuous Variable ◽  
Quantum Circuits ◽  
Quantum Computers ◽  
Classical Simulation ◽  
Efficient Verification ◽  
Quantum Speedup ◽  
Important Milestone ◽  
Boson Sampling

The demonstration of quantum speedup, also known as quantum computational supremacy, that is the ability of quantum computers to outperform dramatically their classical counterparts, is an important milestone in the field of quantum computing. While quantum speedup experiments are gradually escaping the regime of classical simulation, they still lack efficient verification protocols and rely on partial validation. Here we derive an efficient protocol for verifying with single-mode Gaussian measurements the output states of a large class of continuous-variable quantum circuits demonstrating quantum speedup, including Boson Sampling experiments, thus enabling a convincing demonstration of quantum speedup with photonic computing. Beyond the quantum speedup milestone, our results also enable the efficient and reliable certification of a large class of intractable continuous-variable multimode quantum states.

Sign in / Sign up

Export Citation Format

Share Document