scholarly journals Advanced exact synthesis of Clifford+T circuits

2020 ◽  
Vol 19 (9) ◽  
Author(s):  
Philipp Niemann ◽  
Robert Wille ◽  
Rolf Drechsler
Keyword(s):  
Large Scale ◽  
Fault Tolerant ◽  
Logic Synthesis ◽  
Research Problem ◽  
Quantum Systems ◽  
Quantum Circuits ◽  
Research Attention ◽  
Small Quantum ◽  
Significant Research ◽  
Important Research Problem

Abstract Quantum systems provide a new way of conducting computations based on the so-called qubits. Due to the potential for significant speed-ups, this field received significant research attention in recent years. The Clifford+T library is a very promising and popular gate library for these kinds of computations. Unlike other libraries considered so far, it consists of only a small number of gates for all of which robust, fault-tolerant realizations are known for many technologies that seem to be promising for large-scale quantum computing. As a consequence, (logic) synthesis of Clifford+T quantum circuits became an important research problem. However, previous work in this area has several drawbacks: Corresponding approaches are either only applicable to very small quantum systems or lead to circuits that are far from being optimal. The latter is mainly caused by the fact that current synthesis realizes the desired circuit by a local, i.e., column-wise, consideration of the underlying unitary transformation matrix to be synthesized. In this paper, we analyze the conceptual drawbacks of this approach and propose to overcome them by taking a global view of the matrices and perform a separation of concerns regarding individual synthesis steps. We precisely describe a corresponding algorithm as well as its efficient implementation on top of decision diagrams. Experimental results confirm the resulting benefits and show improvements of up to several orders of magnitudes in costs compared to previous work.

scholarly journals A Grid for all Seasons: Enhancing the Integration of Variable Solar and Wind Power in Electricity Systems Across Africa

2021 ◽  
Author(s):  
Sebastian Sterl
Keyword(s):  
Wind Power ◽  
Large Scale ◽  
Power Grids ◽  
Solar Pv ◽  
Renewable Electricity ◽  
African Countries ◽  
Research Attention ◽  
Significant Research ◽  
Power To Gas ◽  
Electricity Access

Abstract Purpose of review This review paper assesses recent scientific findings around the integration of variable renewable electricity (VRE) sources, mostly solar PV and wind power, on power grids across Africa, in the context of expanding electricity access while ensuring low costs and reducing fossil fuel emissions. Recent findings In this context, significant research attention has been given to increased cross-border transmission infrastructure between African countries to harness the spatiotemporal complementarities between renewable electricity resources, as well as to storage options, such as battery storage and power-to-gas. Summary Much of the recent, model-based literature suggests that a combination of increased interconnections in and between Africa’s power pools, leveraging spatiotemporal complementarities between solar PV, wind and hydropower, as well as a large-scale deployment of storage options could help African countries meet their burgeoning power demand with largely decarbonized electricity supply.

scholarly journals An FPGA-Based Quantum Computing Emulation Framework Based on Serial-Parallel Architecture

2016 ◽  
Vol 2016 ◽  
pp. 1-18 ◽  
Author(s):  
Y. H. Lee ◽  
M. Khalil-Hani ◽  
M. N. Marsono
Keyword(s):  
Processing Speed ◽  
Large Scale ◽  
Quantum Algorithms ◽  
Parallel Architecture ◽  
Quantum Systems ◽  
Quantum Circuits ◽  
Proof Of Concept ◽  
Hardware Emulation ◽  
Field Programmable ◽  
Speed Up

Hardware emulation of quantum systems can mimic more efficiently the parallel behaviour of quantum computations, thus allowing higher processing speed-up than software simulations. In this paper, an efficient hardware emulation method that employs a serial-parallel hardware architecture targeted for field programmable gate array (FPGA) is proposed. Quantum Fourier transform and Grover’s search are chosen as case studies in this work since they are the core of many useful quantum algorithms. Experimental work shows that, with the proposed emulation architecture, a linear reduction in resource utilization is attained against the pipeline implementations proposed in prior works. The proposed work contributes to the formulation of a proof-of-concept baseline FPGA emulation framework with optimization on datapath designs that can be extended to emulate practical large-scale quantum circuits.

scholarly journals Quantum teleportation of physical qubits into logical code spaces

2021 ◽  
Vol 118 (36) ◽  
pp. e2026250118
Author(s):  
Yi-Han Luo ◽  
Ming-Cheng Chen ◽  
Manuel Erhard ◽  
Han-Sen Zhong ◽  
Dian Wu ◽  
...  
Keyword(s):  
Quantum Information ◽  
Large Scale ◽  
Fault Tolerant ◽  
Quantum Error Correction ◽  
Quantum Circuits ◽  
Entangled State ◽  
Maximally Entangled State ◽  
Universal Quantum ◽  
Quantum Error ◽  
Logical Qubit

Quantum error correction is an essential tool for reliably performing tasks for processing quantum information on a large scale. However, integration into quantum circuits to achieve these tasks is problematic when one realizes that nontransverse operations, which are essential for universal quantum computation, lead to the spread of errors. Quantum gate teleportation has been proposed as an elegant solution for this. Here, one replaces these fragile, nontransverse inline gates with the generation of specific, highly entangled offline resource states that can be teleported into the circuit to implement the nontransverse gate. As the first important step, we create a maximally entangled state between a physical and an error-correctable logical qubit and use it as a teleportation resource. We then demonstrate the teleportation of quantum information encoded on the physical qubit into the error-corrected logical qubit with fidelities up to 0.786. Our scheme can be designed to be fully fault tolerant so that it can be used in future large-scale quantum technologies.

A Critical Study of Stephen King and Horror Fiction

2019 ◽  
Vol 7 (5) ◽  
pp. 23
Author(s):  
Dr. Sudhir V. Nikam ◽  
Mr. Rajkiran J. Biraje
Keyword(s):  
Research Problem ◽  
Extensive Study ◽  
Serial Killers ◽  
Critical Study ◽  
Research Attention ◽  
Stephen King ◽  
Special Place ◽  
Fiction Writers ◽  
Horror Fiction ◽  
A Site

This present research undertakes the extensive study of horror fiction genre with reference to the select novels of one of the finest and celebrated horror fiction writers of all time, Stephen King. This paper is a substantial assessment of the select horror fiction of King. The research problem revolves extensively around the word fear. Stephen King has conjured up the images of most horrific creatures, monsters, places, and stories, and some of the most enduring villains in fiction. These unimaginable evil beings test the limits of the protagonist. Some of these villains have gone to the extent of becoming as famous (or infamous) as the writer himself. Many of Stephen King villains are monsters of the human variety such as serial killers, power hungry despots, nihilists, etc. His most memorable and monumental characters are the supernatural ones who use their dark powers to twist the orderly world around them into a special place of chaos and pain. It has been assumed that the horror elements in the fiction of Stephen King are the result of his strategic use of supernaturalist and non-supernaturalist elements. The techniques that he uses to evoke horror in reader have been treated as a site for research attention by the researcher.

scholarly journals Fundamental limitations on distillation of quantum channel resources

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Bartosz Regula ◽  
Ryuji Takagi
Keyword(s):  
Lower Bounds ◽  
Quantum Channel ◽  
Quantum Communication ◽  
Fault Tolerant ◽  
State Of The Art ◽  
Quantum Systems ◽  
Noisy Channels ◽  
General Transformation ◽  
Fundamental Limitations ◽  
Strong Converse

AbstractQuantum channels underlie the dynamics of quantum systems, but in many practical settings it is the channels themselves that require processing. We establish universal limitations on the processing of both quantum states and channels, expressed in the form of no-go theorems and quantitative bounds for the manipulation of general quantum channel resources under the most general transformation protocols. Focusing on the class of distillation tasks — which can be understood either as the purification of noisy channels into unitary ones, or the extraction of state-based resources from channels — we develop fundamental restrictions on the error incurred in such transformations, and comprehensive lower bounds for the overhead of any distillation protocol. In the asymptotic setting, our results yield broadly applicable bounds for rates of distillation. We demonstrate our results through applications to fault-tolerant quantum computation, where we obtain state-of-the-art lower bounds for the overhead cost of magic state distillation, as well as to quantum communication, where we recover a number of strong converse bounds for quantum channel capacity.

scholarly journals Questioning Racial and Gender Bias in AI-based Recommendations: Do Espoused National Cultural Values Matter?

2021 ◽  
Author(s):  
Manjul Gupta ◽  
Carlos M. Parra ◽  
Denis Dennehy
Keyword(s):  
United States ◽  
Cultural Values ◽  
Gender Bias ◽  
The United States ◽  
Compelling Evidence ◽  
Research Attention ◽  
Academic Literature ◽  
Gender Biases ◽  
Significant Research ◽  
And Gender

AbstractOne realm of AI, recommender systems have attracted significant research attention due to concerns about its devastating effects to society’s most vulnerable and marginalised communities. Both media press and academic literature provide compelling evidence that AI-based recommendations help to perpetuate and exacerbate racial and gender biases. Yet, there is limited knowledge about the extent to which individuals might question AI-based recommendations when perceived as biased. To address this gap in knowledge, we investigate the effects of espoused national cultural values on AI questionability, by examining how individuals might question AI-based recommendations due to perceived racial or gender bias. Data collected from 387 survey respondents in the United States indicate that individuals with espoused national cultural values associated to collectivism, masculinity and uncertainty avoidance are more likely to question biased AI-based recommendations. This study advances understanding of how cultural values affect AI questionability due to perceived bias and it contributes to current academic discourse about the need to hold AI accountable.

scholarly journals Excitation of Small Quantum Systems by High-Frequency Fields

1996 ◽  
Vol 77 (18) ◽  
pp. 3763-3766 ◽  
Author(s):  
Naama Brenner ◽  
Shmuel Fishman
Keyword(s):  
High Frequency ◽  
Quantum Systems ◽  
Small Quantum

Context-aware Adaptive Surgery

2021 ◽  
Vol 5 (3) ◽  
pp. 1-22
Author(s):  
Hongli Wang ◽  
Bin Guo ◽  
Jiaqi Liu ◽  
Sicong Liu ◽  
Yungang Wu ◽  
...  
Keyword(s):  
Real Time ◽  
Large Scale ◽  
Resource Constraints ◽  
Search Algorithm ◽  
Search Time ◽  
State Graph ◽  
Context Aware ◽  
Optimal Partition ◽  
Research Attention ◽  
Neighbor Effect

Deep Neural Networks (DNNs) have made massive progress in many fields and deploying DNNs on end devices has become an emerging trend to make intelligence closer to users. However, it is challenging to deploy large-scale and computation-intensive DNNs on resource-constrained end devices due to their small size and lightweight. To this end, model partition, which aims to partition DNNs into multiple parts to realize the collaborative computing of multiple devices, has received extensive research attention. To find the optimal partition, most existing approaches need to run from scratch under given resource constraints. However, they ignore that resources of devices (e.g., storage, battery power), and performance requirements (e.g., inference latency), are often continuously changing, making the optimal partition solution change constantly during processing. Therefore, it is very important to reduce the tuning latency of model partition to realize the real-time adaption under the changing processing context. To address these problems, we propose the Context-aware Adaptive Surgery (CAS) framework to actively perceive the changing processing context, and adaptively find the appropriate partition solution in real-time. Specifically, we construct the partition state graph to comprehensively model different partition solutions of DNNs by import context resources. Then "the neighbor effect" is proposed, which provides the heuristic rule for the search process. When the processing context changes, CAS adopts the runtime search algorithm, Graph-based Adaptive DNN Surgery (GADS), to quickly find the appropriate partition that satisfies resource constraints under the guidance of the neighbor effect. The experimental results show that CAS realizes adaptively rapid tuning of the model partition solutions in 10ms scale even for large DNNs (2.25x to 221.7x search time improvement than the state-of-the-art researches), and the total inference latency still keeps the same level with baselines.

Single Chip Microcomputer Cluster Management

2014 ◽  
Vol 933 ◽  
pp. 584-589
Author(s):  
Zhi Chun Zhang ◽  
Song Wei Li ◽  
Wei Ren Wang ◽  
Wei Zhang ◽  
Li Jun Qi
Keyword(s):  
Real Time ◽  
Management System ◽  
Large Scale ◽  
Fault Tolerant ◽  
Single Chip ◽  
Single Chip Microcomputer ◽  
Cluster Management ◽  
The Real ◽  
Time Performance ◽  
Operational Phase

This paper presents a system in which the cluster devices are controlled by single-chip microcomputers, with emphasis on the cluster management techniques of single-chip microcomputers. Each device in a cluster is controlled by a single-chip microcomputer collecting sample data sent to and driving the device by driving data received from the same cluster management computer through COMs. The cluster management system running on the cluster management computer carries out such control as initial SCM identification, run time slice management, communication resource utilization, fault tolerance and error corrections on single-chip microcomputers. Initial SCM identification is achieved by signal responses between the single-chip microcomputers and the cluster management computer. By using the port priority and the parallelization of serial communications, the systems real-time performance is maximized. The real-time performance can be adjusted and improved by increasing or decreasing COMs and the ports linked to each COM, and the real-time performance can also be raised by configuring more cluster management computers. Fault-tolerant control occurs in the initialization phase and the operational phase. In the initialization phase, the cluster management system incorporates unidentified single-chip microcomputers into the system based on the history information recorded on external storage media. In the operational phase, if an operation error of reading and writing on a single-chip microcomputer reaches a predetermined threshold, the single-chip microcomputer is regarded as serious fault or not existing. The cluster management system maintains accuracy maintenance database on external storage medium to solve nonlinear control of specific devices and accuracy maintenance due to wear. The cluster management system uses object-oriented method to design a unified driving framework in order to enable the implementation of the cluster management system simplified, standardized and easy to transplant. The system has been applied in a large-scale simulation system of 230 single-chip microcomputers, which proves that the system is reliable, real-time and easy to maintain.

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