Basics and Applications of Quantum Annealing

Shu Tanaka

Shu Tanaka, Kotaro TANAHASHI, Tomomitsu Motohashi +1 more

Quantum annealing (QA) is a promising calculation method for obtaining a better solution to combinatorial optimization problems. QA is a natural computation technique proposed in the context of statistical physics in 1998. In 2011, the world's first commercial machine realizing QA experimentally was released. After that, the development of hardware and software has been exhaustive, and the studies on application search have been done using commercial QA machines. In this paper, we first explain the basics of QA without assuming the knowledge of statistical physics and quantum physics. We also show a couple of examples of application studies on QA. In addition, existing problems and overcoming other methods are explained.

Kristel F. L. Michielsen

Siyuan Han

This chapter focuses on the application of Nb Josephson junctions (JJs) in quantum annealing (QA). It begins with a brief introduction to diffident strategies for implementing quantum computation (QC) with an emphasis on quantum annealing. The chapter presents the basic physics of the simplest superconducting flux qubit: radio frequency superconducting quantum interference devices (RF-SQUID). It gives a brief description on the design and realization of couplers, and control and measurement circuitry using Nb Josephson junctions. The chapter describes a scalable architecture upon which quantum annealing processors consisting up to 1024 superconducting flux qubits made of more than 104 Nb Josephson junctions. It discusses evidence on whether D-Wave 2X, which is the latest quantum annealing processor available, works as expected. The chapter also focuses on the physics and application of RF-SQUID flux qubits because the fundamental building blocks of the most advanced quantum annealers demonstrated so far are variations of superconducting flux qubits with one Josephson junction, a.k.a. the RF-SQUID.

Arnab Das, Bikas K. Chakrabarti

Meigen Zhang

The idea of Quantum Annealing(QA),which is based on the mechanism of quantum transition tunneling effect and not same with the annealing theory of simulated thermal annealing,is a recent offspring of the celebrated simulated thermal annealing by Kirkpatrick.This paper,firstly,summarizes the basic differences between Quantum Annealing and Simulated Annealing;and then mainly addresses the attention to the practical developments of the application in optimization such as Ising spin glass,Traveling Salesman Problem,Boolean Satisfiability Problem and so on,discusses the details of the annealing process of Quantum Annealing and its compare with Simulated Annealing on test problems;subsequently,expatiates the geophysical inverse theory and method corresponding to Quantum Annealing,discusses the setting of parameters such as Temperature and Transverse field,compares the probabilities of being on configurations with different transverse fields and potential energies;finally briefly summarizes the prospects and the existent problems of using Quantum Annealing in geophysical inverse problem.