After a year of outside investigation, questions remain about a controversial quantum computer. When in 1935 physicist Erwin Schrodinger proposed his thought experiment involving a cat that could be both dead and alive, he could have been talking about D-Wave Systems. The Canadian start-up is the maker of what it claims is the world's first commercial-scale quantum computer. But exactly what its computer does and how well it does it remain as frustratingly unknown as the health of Schrodinger's poor puss. D-Wave has succeeded in attracting bigname customers such as Google and Lockheed Martin Corp. But many scientists still doubt the long-term viability of D-Wave's technology, which has defied scientific understanding of quantum computing from the start.
After a year of outside investigation, questions remain about a controversial quantum computer. When in 1935 physicist Erwin Schrodinger proposed his thought experiment involving a cat that could be both dead and alive, he could have been talking about D-Wave Systems. The Canadian start-up is the maker of what it claims is the world's first commercial-scale quantum computer. But exactly what its computer does and how well it does it remain as frustratingly unknown as the health of Schrodinger's poor puss. D-Wave has succeeded in attracting bigname customers such as Google and Lockheed Martin Corp. But many scientists still doubt the long-term viability of D-Wave's technology, which has defied scientific understanding of quantum computing from the start.
On May 2011, D-Wave Systems Inc. announced "D-Wave One", as "the world's first commercially available quantum computer". No wonder this adiabatic quantum computer based on 128-qubit chip-set provoked an immediate controversy. Over the last 40 years, quantum computation has been a very promising yet challenging research area, facing major difficulties producing a large scale quantum computer. Today, after Google has purchased "D-Wave Two" containing 512 qubits, criticism has only increased. In this work, we examine the theory underlying the D-Wave, seeking to shed some light on this intriguing quantum computer. Starting from classical algorithms such as Metropolis algorithm, genetic algorithm (GA), hill climbing and simulated annealing, we continue to adiabatic computation and quantum annealing towards better understanding of the D-Wave mechanism. Finally, we outline some applications within the fields of information and image processing. In addition, we suggest a few related theoretical ideas and hypotheses.
In 1935 Erwin Schrödinger proposed a thought experiment to show the absurd consequences of applying quantum mechanics to everyday objects. Schrödinger imagined placing a cat in a box, along with a vial of deadly poison that is connected to a radioactive atom. If the atom decays, it releases the poison and kills the cat. When the box is closed we do not know if the atom has decayed or not, which means that it can be in a "superposition" of two states (decayed and non-decayed) at the same time. Therefore, protested Schrödinger, the cat can be both dead and alive at the same time – which is clearly absurd. There was obviously, he thought, some boundary between the microscopic world of atoms and quantum mechanics, and the macroscopic world of cats and classical mechanics.
Erwin Schrodinger first described the thought-experiment which has since become known as 'the paradox of Schrodinger's cat' 51 years ago. In recent years, popular accounts of quantum mechanics have tended to adopt one or other of the philosophically most extreme solutions to this paradox, i.e. the consciousness hypothesis or the many worlds interpretation. The author attempts to redress the balance by describing what he takes to be the orthodox solution to the paradox which explains the paradox, without recourse to such counterintuitive notions as a cat simultaneously dead and alive or a universe continually splitting into multiple worlds, as being due to a misapplication of the quantum formalism.
HE FIRST THIRD of the 20 th century saw the collapse of many absolutes.Albert Einstein's 1905 special relativity theory eliminated the notion of absolute time, while Kurt Gödel's 1931 incompleteness theorem questioned the notion of absolute mathematical truth.Most profoundly, however, quantum mechanics raised doubts on the notion of absolute objective reality.Is Schrödinger's cat dead or alive?Nearly 100 years after quantum mechanics was introduced, scientists still are not in full agreement on what it means.The problem with objective reality stems from the superposition principle.In a nutshell, quantum systems can exist in a superposition of their possible observable states before measurement.While a classical bit has a unique value, 0 or 1, a quantum bit, or qubit, exists as a superposition of two classical bits.The physicist Richard Feynman hinted at the possibility of using quantum effects for computation in his 1959 lecture, "There's Plenty of Room at the Bottom."But this possibility seemed somewhat remote, until Peter Shor's seminal 1994 paper, where he showed it is theoretically possible to use quantum computation to factor numbers in polynomial time, which would break current public-key cryptographic schemes.This made the realization of quantum computing one of the holy grails of computing in the 21 st century.In fact, quantum computing is an important part of one of the U.S. National Science Foundation's "Ten Big Ideas."The popular media regularly reports breathlessly on quantum computing: "Quantum computing will break your encryption in a few years"; "Why quantum's computing time is now"; and "The computer that could rule the world."Yet the physical realization of quantum comput-e https://bit.ly/2uq1r0fSee p. 15 for more on the quantum argument.
Erwin Schrödinger is famous for presenting his wave equation of motion that jump-started quantum mechanics. His disenchantment with the Copenhagen interpretation of quantum mechanics led him to unveil the Schrödinger's cat paradox, which did not get much attention for nearly half a century. In the meantime, disappointment with quantum mechanics turned his interest to biology facilitating, albeit in a peripheral way, the revelation of the structure of DNA. Interest in Schrödinger's cat has recently come roaring back making its appearance conspicuously in numerous scientific articles. From the arguments presented here, it would appear that the legendary Schrödinger's cat is here to stay, symbolizing a profound truth that quantum reality exists at all scales; but we do not observe it in our daily macroscopic world as it is masked for all practical purposes, most likely by environmental decoherence with irreversible thermal effects. Quanta 2017; 6: 70–80.
In 1935, Erwin Schrödinger suggested his famous gedanken experiment of the cat that is simultaneously "dead" and "alive" inside its box until the box is opened. But as Tesche explains in her Perspective, such a macroscopic manifestation of quantum mechanics has remained elusive until recently. The experiments by van der Wal et al. are an important step toward demonstrating that quantum mechanics can describe macroscopic phenomena. The approach may be exploited in quantum computing and quantum cryptography.