I am a staff scientist at the National Institute of Standards and Technology (NIST), in the Applied and Computational Mathematics Division. I am also a Fellow and adjunct professor at the NIST-UMD Joint Center for Quantum Information and Computer Science (QuICS). I do research on quantum computation and theoretical computer science, in particular, quantum algorithms and complexity, quantum state tomography, machine learning, and quantum cryptography.
Previously I was a postdoc in Computer Science at UC Berkeley, and a postdoc at the Institute for Quantum Information at Caltech. I received a PhD in computer science from UC San Diego, and a BA in mathematics from Princeton.You can reach me via e-mail at: yi-kai.liu |at| nist |dot| gov or at: yikailiu00 |at| gmail |dot| com
This page was last updated on: Nov. 23, 2016.
QuICS is hosting QCrypt 2016, the 6th International Conference on Quantum Cryptography, Sept. 12-16, 2016, in Washington, DC!
Low-rank Methods for Learning Quantum States (joint work with S. Becker, B. Brown, J. Eisert, S. T. Flammia and D. Gross), Workshop on Low-rank Methods for Large-scale Machine Learning, NIPS 2010.
Preparing Lattice Superpositions on a Quantum Computer, Workshop on Post-Quantum Information Security, Joint Quantum Institute, Oct. 2010.
N-representability is QMA-complete (joint work with M. Christandl and F. Verstraete), Workshop on Quantum Marginals and Density Matrices, Fields Institute, July 2009.
Y.-K. Liu, "Quantum information: Show, don't tell," Nature Physics (2014) [doi] ("news and views" article about quantum PCA).
C. Boutin, "Quantum Physics Could Make Secure, Single-Use Computer Memories Possible," NIST Tech Beat, Jan. 14, 2014 [link].
CS138 Computer Algorithms, Spring 2009 (a course on approximation algorithms for combinatorial optimization, at Caltech).
Papers (or try the handy Arxiv listing)
Y.-K. Liu, "Building One-Time Memories from Isolated Qubits," Innovations in Theoretical Computer Science (ITCS) 2014, pp.269-286; Arxiv:1304.5007.
C. Shen, R. W. Heeres, P. Reinhold, L. Jiang, Y.-K. Liu, R. J. Schoelkopf, and L. Jiang, "Optimized Tomography of Continuous Variable Systems Using Excitation Counting," Phys. Rev. A 94, 052327 [doi]. ArXiv:1606.07554.
S. Kimmel and Y.-K. Liu, "Quantum Compressed Sensing Using 2-Designs," Arxiv:1510.08887.
F. Krahmer and Y.-K. Liu, "Phase Retrieval Without Small-Ball Probability Assumptions," arXiv:1604.07281.
J. Conroy, S. T. Davis, J. Kubina, Y.-K. Liu, D. P. O’Leary and J. D Schlesinger, "Multilingual Summarization: Dimensionality Reduction and a Step Towards Optimal Term Coverage," MultiLing 2013 (Workshop on Multilingual Multi-document Summarization), pp.55-63 [link].
S. T. Flammia, D. Gross, Y.-K. Liu and J. Eisert, "Quantum Tomography via Compressed Sensing: Error Bounds, Sample Complexity, and Efficient Estimators," New J. Phys. 14, 095022 (2012) [link]. ArXiv:1205.2300.
A. Anandkumar, D. P. Foster, D. Hsu, S. M. Kakade and Y.-K. Liu, "A Spectral Algorithm for Latent Dirichlet Allocation," Algorithmica 72 (1), pp.193-214 (2015) [doi]. Conference version: Advances in Neural Information Processing Systems (NIPS), pp.926-934 (2012) [link]. ArXiv:1204.6703.
M. Ohliger, V. Nesme, D. Gross, Y.-K. Liu and J. Eisert, "Continuous-variable quantum compressed sensing," ArXiv:1111.0853.
M. Cramer, M. B. Plenio, S. T. Flammia, R. Somma, D. Gross, S. D. Bartlett, O. Landon-Cardinal, D. Poulin and Y.-K. Liu, "Efficient Quantum State Tomography," Nature Commun. 1, 149 (2010) [link]. ArXiv:1101.4366.
O. Landon-Cardinal, Y.-K. Liu and D. Poulin, "Efficient Direct Tomography for Matrix Product States," ArXiv:1002.4632.[link]; ArXiv:1210.0787.
A. Ambainis, A. M. Childs and Y.-K. Liu, "Quantum property testing for bounded-degree graphs," Proc. RANDOM 2011, Lecture Notes in Computer Science 6845, pp.365-376. ArXiv:1012.3174.
Y.-K. Liu, "Quantum Algorithms Using the Curvelet Transform," Proc. ACM Symposium on Theory of Computing (STOC), pp.391-400, 2009. ArXiv:0810.4968.
Y.-K. Liu, "The Local Consistency Problem for Stoquastic and 1-D Quantum Systems," submitted. ArXiv:0712.1388.
Y.-K. Liu, "The Complexity of the Consistency and N-representability Problems for Quantum States," PhD thesis, Univ. of California, San Diego, 2007. ArXiv:0712.3041.
Y.-K. Liu, "Consistency of Local Density Matrices is QMA-complete," Proc. RANDOM 2006, pp.438-449; Arxiv preprint: quant-ph/0604166.
Y.-K. Liu, V. Lyubashevsky and D. Micciancio, "On Bounded Distance Decoding for General Lattices," Proc. RANDOM 2006, pp.450-461.
K. Levchenko and Y.-K. Liu, "Counting Solutions of Polynomial Equations"
A. Blanc, Y.-K. Liu and A. Vahdat, "Designing Incentives for
Peer-to-Peer Routing," Proc. INFOCOM 2005, pp.374-385