PREVIEW / CITATION / ENGLISH - "[...] The original motivation to build a quantum computer came from Feynman¹, who imagined a machine capable of simulating generic quantum mechanical systems—a task that is believed to be intractable for classical computers. Such a machine could have far-reaching applications in the simulation of many-body quantum physics in condensed-matter, chemical and high-energy systems. Part of Feynman’s challenge was met by Lloyd², who showed how to approximately decompose the time evolution operator of interacting quantum particles into a short sequence of elementary gates, suitable for operation on a quantum computer. However, this left open the problem of how to simulate the equilibrium and static properties of quantum systems. This requires the preparation of ground and Gibbs states on a quantum computer. For classical systems, this problem is solved by the ubiquitous Metropolis algorithm³, a method that has basically acquired a monopoly on the simulation of interacting particles. Here we demonstrate how to implement a quantum version of the Metropolis algorithm. This algorithm permits sampling directly from the eigenstates of the Hamiltonian, and thus evades the sign problem present in classical simulations. A small-scale implementation of this algorithm should be achievable with today’s technology. [...]"

[1] Feynman, R. Simulating physics with computers. Int. J. Theor. Phys. 21, 467–488 (1982)
[2] Lloyd, S. Universal quantum simulators. Science 273, 1073–1078 (1996)
[3] Metropolis, N., Rosenbluth, A. W., Rosenbluth, M. N., Teller, A. H. & Teller, E. Equation of state calculation by fast computing machines. J. Chem. Phys. 21, 1087 (1953)

Nature Volume: 471, Pages: 87–90
DOI: 10.1038/nature09770

Project Part:

P04 Quantum Impurity Solvers / Frank Verstraete

External Link:

Nature

External Link:

Verstraete Group / Quantum Optics, Quantum Nanophysics and Quantum Information / Faculty of Physics / University of Vienna

External Link:

Quantum Optics, Quantum Nanophysics and Quantum Information / Faculty of Physics / University of Vienna

External Link:

VCQ - Vienna Center for Quantum Science and Technology

External Link:

University of Vienna / Öffentlichkeitsarbeit und Veranstaltungsmanagement