65,844 research outputs found
The Road to Quantum Computational Supremacy
We present an idiosyncratic view of the race for quantum computational
supremacy. Google's approach and IBM challenge are examined. An unexpected
side-effect of the race is the significant progress in designing fast classical
algorithms. Quantum supremacy, if achieved, won't make classical computing
obsolete.Comment: 15 pages, 1 figur
Programming Quantum Computers Using Design Automation
Recent developments in quantum hardware indicate that systems featuring more
than 50 physical qubits are within reach. At this scale, classical simulation
will no longer be feasible and there is a possibility that such quantum devices
may outperform even classical supercomputers at certain tasks. With the rapid
growth of qubit numbers and coherence times comes the increasingly difficult
challenge of quantum program compilation. This entails the translation of a
high-level description of a quantum algorithm to hardware-specific low-level
operations which can be carried out by the quantum device. Some parts of the
calculation may still be performed manually due to the lack of efficient
methods. This, in turn, may lead to a design gap, which will prevent the
programming of a quantum computer. In this paper, we discuss the challenges in
fully-automatic quantum compilation. We motivate directions for future research
to tackle these challenges. Yet, with the algorithms and approaches that exist
today, we demonstrate how to automatically perform the quantum programming flow
from algorithm to a physical quantum computer for a simple algorithmic
benchmark, namely the hidden shift problem. We present and use two tool flows
which invoke RevKit. One which is based on ProjectQ and which targets the IBM
Quantum Experience or a local simulator, and one which is based on Microsoft's
quantum programming language Q.Comment: 10 pages, 10 figures. To appear in: Proceedings of Design, Automation
and Test in Europe (DATE 2018
Pulse Width Modulation for Speeding Up Quantum Optimal Control Design
This paper focuses on accelerating quantum optimal control design for complex
quantum systems. Based on our previous work [{arXiv:1607.04054}], we combine
Pulse Width Modulation (PWM) and gradient descent algorithm into solving
quantum optimal control problems, which shows distinct improvement of
computational efficiency in various cases. To further apply this algorithm to
potential experiments, we also propose the smooth realization of the optimized
control solution, e.g. using Gaussian pulse train to replace rectangular
pulses. Based on the experimental data of the D-Norleucine molecule, we
numerically find optimal control functions in -qubit and -qubit systems,
and demonstrate its efficiency advantage compared with basic GRAPE algorithm
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