We address the question of how a quantum computer can be used to simulate experiments on quantum systems in thermal equilibrium. We present two approaches for the preparation of the equilibrium state on a quantum computer. For both approaches, we show that the output state of the algorithm, after long enough time, is the desired equilibrium. We present a numerical analysis of one of these approaches for small systems. We show how equilibrium (time-)correlation functions can be efficiently estimated on a quantum computer, given a preparation of the equilibrium state. The quantum algorithms that we present are hard to simulate on a classical computer. This indicates that they could provide an exponential speedup over what can be achieved with a classical device.
|Pages (from-to)||022301-1 - 022301-22|
|Number of pages||22|
|Journal||Physical Review A - Atomic, Molecular, and Optical Physics|
|Publication status||Published - 2000|
Terhal, B. M., & DiVincenzo, D. P. (2000). Problem of equilibration and the computation of correlation functions on a quantum computer. Physical Review A - Atomic, Molecular, and Optical Physics, 61(2), 022301-1 - 022301-22. . https://doi.org/10.1103/PhysRevA.61.022301