Demon-like algorithmic quantum cooling and its realization with quantum optics

  • A Corrigendum to this article was published on 28 February 2014


Simulation of the low-temperature properties of many-body systems remains one of the major challenges in theoretical1,2,3 and experimental4,5,6 quantum information science. We present, and demonstrate experimentally, a universal (pseudo) cooling method that is applicable to any physical system that can be simulated by a quantum computer7,8,9. This method allows us to distil and eliminate hot components of quantum states like a quantum Maxwell's demon11,10. The experimental implementation is realized with a quantum optical network, and the results are in full agreement with theoretical predictions (with fidelity higher than 0.978). Applications of the proposed pseudo-cooling method include simulations of the low-temperature properties of physical and chemical systems that are intractable with classical methods.

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Figure 1: Basic principle of the pseudo-cooling method.
Figure 2: Experimental details.
Figure 3: Experimental results.
Figure 4: Experimental results.

Change history

  • 05 February 2014

    In the version of this Letter originally published online and in print, the affiliation of Sergio Boixo was incorrectly given. He is affiliated with the Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA. This has now been corrected in the HTML and PDF versions of this Letter.


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The authors thank A. Eisfeld, I. Kassal, J. Taylor and J. Whitfield for insightful discussions and R. Babbush, S. Mostame and D. Tempel for useful comments and suggestions on the manuscript. The authors acknowledge the following funding sources: National Science Foundation award no. CHE-1037992, Croucher Foundation (to M.H.Y.); Defense Advanced Research Projects Agency under the Young Faculty Award N66001-09-1-2101-DOD35CAP, the Camille and Henry Dreyfus Foundation and the Sloan Foundation; Defense Advanced Research Projects Agency award no. N66001-09-1-2101 (to S.B.); the National Basic Research Program of China (grant no. 2011CB921200), the National Natural Science Foundation of China (grants nos 11274297, 11004185, 61322506, 60921091, 11274289, 11325419, 61327901 and 11174270), the Fundamental Research Funds for the Central Universities (grant nos WK 2030020019 and WK2470000011), the Program for New Century Excellent Talents in University (NCET-12-0508), the Science Foundation for the Excellent PHD Thesis (grant no. 201218) and the Chinese Academy of Sciences. M.H.Y. acknowledges support from the National Basic Research Program of China (grants 2011CBA00300, 2011CBA00301) and the National Natural Science Foundation of China (grants 61033001 and 61061130540).

Author information




M.-H.Y. and A.A.-G. are responsible for the main theoretical idea behind the pseudo-cooling method. S.B. performed detailed analysis on the scaling behaviour of the pseudo-cooling method. M.-H.Y. drafted the preliminary experimental proposal, which was put forward by Z.-W.Z. and C.-F.L. The detailed experimental procedures were designed and carried out by J.-S.X., assisted by X.-Y.X. The experiment was supervised by C.-F.L. and G.-C.G. All authors contributed to writing the manuscript and discussed the experimental procedures and results.

Corresponding authors

Correspondence to Chuan-Feng Li or Alán Aspuru-Guzik.

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Xu, J., Yung, M., Xu, X. et al. Demon-like algorithmic quantum cooling and its realization with quantum optics. Nature Photon 8, 113–118 (2014).

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