Abstract
Many proposed architectures for quantum computing involve arranging qubits in a lattice, and then using swap gates to move the quantum states between qubits to enable any pair of qubits to interact with each other. Since swap gates perform no useful computation, they can be viewed as an overhead whose number should be minimised in efficient quantum programs. The location of the swap gates in a quantum circuit are chosen by minimising an objective function characterising the structure of the quantum circuit. Those which currently offer the lowest swap cost reduce the significance of each gate to the objective function relative to its position in the circuit. The criterion that describes how quickly the significance must decrease. In this paper, we show that to satisfy this criterion, it is necessary and sufficient for the decay to be exponential. However, when applying this new objective function, there is no significant improvement over the old function, with most of the benchmark circuits having less than 5% improvement. Only three circuits had more than 10% improvement in swap cost, and these circuits were all less than 100 gates long. The three longest circuits in the benchmark suite had less than 1% change in swap cost. There is also a significant penalty in run time, in one case reaching 265.48%.
Original language  English 

Title of host publication  Embedded Computer Systems 
Subtitle of host publication  Architectures, Modeling, and Simulation  19th International Conference, SAMOS 2019, Proceedings 
Editors  Dionisios N. Pnevmatikatos, Maxime Pelcat, Matthias Jung 
Publisher  SpringerVerlag 
Pages  348357 
Number of pages  10 
ISBN (Print)  9783030275617 
DOIs  
Publication status  Published  08 Aug 2019 
Event  19th International Conference on Embedded Computer Systems: Architectures, Modeling, and Simulation, SAMOS 2019  Samos, Greece Duration: 07 Jul 2019 → 11 Jul 2019 
Publication series
Name  Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) 

Volume  11733 LNCS 
ISSN (Print)  03029743 
ISSN (Electronic)  16113349 
Conference
Conference  19th International Conference on Embedded Computer Systems: Architectures, Modeling, and Simulation, SAMOS 2019 

Country/Territory  Greece 
City  Samos 
Period  07/07/2019 → 11/07/2019 
ASJC Scopus subject areas
 Theoretical Computer Science
 Computer Science(all)
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Dive into the research topics of 'Comparison of Exponentially Decreasing Vs. Polynomially Decreasing Objective Functions for Making Quantum Circuits Nearest Neighbour Compliant'. Together they form a unique fingerprint.Student Theses

The synthesis of nearest neighbour compliant quantum circuits
Author: Rogers, L., Jul 2021Supervisor: McAllister, J. (Supervisor) & Paternostro, M. (Supervisor)
Student thesis: Doctoral Thesis › Doctor of Philosophy
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