Quantum principal component analysis

The usual way to reveal properties of an unknown quantum state, given many copies of a system in that state, is to perform measurements of different observables and to analyse the results statistically. For non-sparse but low-rank quantum states, revealing eigenvectors and corresponding eigenvalues...

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Bibliographic Details
Main Authors: Lloyd, Seth (Contributor), Mohseni, Masoud (Author), Rebentrost, Frank Patrick (Contributor)
Other Authors: Massachusetts Institute of Technology. Department of Mechanical Engineering (Contributor), Massachusetts Institute of Technology. Research Laboratory of Electronics (Contributor)
Format: Article
Language:English
Published: Nature Publishing Group, 2015-07-01T18:41:03Z.
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Online Access:Get fulltext
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100 1 0 |a Lloyd, Seth  |e author 
100 1 0 |a Massachusetts Institute of Technology. Department of Mechanical Engineering  |e contributor 
100 1 0 |a Massachusetts Institute of Technology. Research Laboratory of Electronics  |e contributor 
100 1 0 |a Lloyd, Seth  |e contributor 
100 1 0 |a Rebentrost, Frank Patrick  |e contributor 
700 1 0 |a Mohseni, Masoud  |e author 
700 1 0 |a Rebentrost, Frank Patrick  |e author 
245 0 0 |a Quantum principal component analysis 
260 |b Nature Publishing Group,   |c 2015-07-01T18:41:03Z. 
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520 |a The usual way to reveal properties of an unknown quantum state, given many copies of a system in that state, is to perform measurements of different observables and to analyse the results statistically. For non-sparse but low-rank quantum states, revealing eigenvectors and corresponding eigenvalues in classical form scales super-linearly with the system dimension. Here we show that multiple copies of a quantum system with density matrix ρ can be used to construct the unitary transformation e[superscript −iρt]. As a result, one can perform quantum principal component analysis of an unknown low-rank density matrix, revealing in quantum form the eigenvectors corresponding to the large eigenvalues in time exponentially faster than any existing algorithm. We discuss applications to data analysis, process tomography and state discrimination. 
520 |a United States. Defense Advanced Research Projects Agency 
520 |a United States. National Aeronautics and Space Administration. Quantum Artificial Intelligence Laboratory 
520 |a United States. Air Force Office of Scientific Research. Multidisciplinary University Research Initiative 
546 |a en_US 
655 7 |a Article 
773 |t Nature Physics