
QuICS Hartree Postdoctoral Fellow, 2014present Joint Center for Quantum Information and Computer Science University of Maryland
Postdoctoral Fellow, 20102014

My research focuses on the theory of quantum information and its applications to algorithms, complexity theory and cryptography. Specific topics that I am currently interested in include algebraic geometry applications in quantum information theory, the theory of entanglement and quantum channels.
Jianxin Chen, Cheng Guo, Zhengfeng Ji, YiuTung Poon, Nengkun Yu, Bei Zeng, Jie Zhou
Joint Product Numerical Range and Geometry of Reduced Density Matrices.
Available as arXiv.org ePrint 1606.07422
Tao Xin, Dawei Lu, Joel Klassen, Nengkun Yu, Zhengfeng Ji, Jianxin Chen, Xian Ma, Guilu Long, Bei Zeng, Raymond Laflamme.
Quantum State Tomography Via Reduced Density Matrices.
Available as arXiv.org ePrint 1604.02046
Jianxin Chen, Nathanial Johnston, ChiKwong Li, Sarah Plosker.
Quantifying the Coherence of Pure Quantum States.
Available as arXiv.org ePrint 1601.06269
Xian Ma, Tyler Jackson, Hui Zhou, Jianxin Chen, Dawei Lu, Michael D. Mazurek, Kent A. G. Fisher, Xinhua Peng, David Kribs, Kevin J. Resch,Zhengfeng Ji, Bei Zeng, Raymond Laflamme.
PureState Tomography with the Expectation Value of Pauli Operators.
Physical Review A 93 (3), 032140
Also available as arXiv.org ePrint 1601.05379
Dawei Lu, Tao Xin, Nengkun Yu, Zhengfeng Ji, Jianxin Chen, Guilu Long, Jonathan Baugh, Xinhua Peng, Bei Zeng, Raymond Laflamme.
Tomography is Necessary for Universal Entanglement Detection with SingleCopy Observables.
Physical Review Letters 116 (23), 230501
Also available as arXiv.org ePrint 1511.00581
Jianxin Chen, Zhengfeng Ji, Nengkun Yu, Bei Zeng.
Detecting Consistency of Overlapping Quantum Marginals by Separability
Physical Review A 93 (3), 032105
Also available as arXiv.org ePrint 1509.06591
Jianxin Chen, Zhengfeng Ji, ChiKwong Li, YiuTung Poon, Yi Shen, Nengkun Yu, Bei Zeng, Duanlu Zhou.
Discontinuity of Maximum Entropy Inference and Quantum Phase Transitions.
New Journal of Physics 17 (8), 083019, 2015
Also available as arXiv.org ePrint 1406.5046
Jianxin Chen, Nathaniel Johnston.
The Minimum Size of Unextendible Product Bases in the Bipartite Case (and Some Multipartite Cases).
Communications in Mathematical Physics 333 (1), 351365
Also available as arXiv.org ePrint 1301.1406
Lin Chen,Jianxin Chen, Dragomir Ž Đoković, Bei Zeng.
Universal Subspaces for Local Unitary Groups of Fermionic Systems.
Communications in Mathematical Physics 333 (2), 541563
Also available as arXiv.org ePrint 1301.3421
Jianxin Chen, Zhengfeng Ji, Mary Beth Ruskai, Bei Zeng, Duanlu Zhou
Principle of Maximum Entropy and Quantum Phase Transitions
Submitted.
Also available as arXiv.org ePrint 1406.5046
Jianxin Chen, Lin Chen, Bei Zeng.
Unextendible Product Basis for Fermionic Systems.
Journal of Mathematical Physics, 55, 082207, 2014.
Also available as arXiv.org ePrint 1312.4218
Jianxin Chen, Zhengfeng Ji, David Kribs, Norbert Lütkenhaus, Bei Zeng.
Symmetric Extension of TwoQubit States.
Physical Review A, 90:032318, 2014.
Also available as arXiv.org ePrint 1310.3530
Joel Klassen, Jianxin Chen, Bei Zeng.
Universal Entanglers for Bosonic and Fermionic Systems.
Presented at 8th Conference on the Theory of Quantum Computation, Communication and Cryptography (TQC 2013), Guelph, Canada, 2013
Also available as arXiv.org ePrint 1305.7489
Salman Beigi, Jianxin Chen, Markus Grassl, Zhengfeng Ji, Qiang Wang, Bei Zeng.
Symmetries of Codeword Stabilized Quantum Codes.
Presented at 8th Conference on the Theory of Quantum Computation, Communication and Cryptography(TQC 2013), Guelph, Canada, 2013
Also available as arXiv.org ePrint 1303.7020
Lin Chen, Jianxin Chen, Dragomir Z. Djokovic, Bei Zeng.
Universal Subspaces for Local Unitary Groups of Fermionic Systems.
Communications in Mathematical Physics
Also available as arXiv.org ePrint 1301.3421
Jianxin Chen, and Nathaniel Johnston.
The Minimum Size of Unextendible Product Bases in the Bipartite Case (and Some Multipartite Cases).
Communications in Mathematical Physics
Also available as arXiv.org ePrint 1301.1406
Uniqueness of Quantum States Compatible with Given Measurement Results.
Physical Review A, 88:012109, 2013.
Also available as arXiv.org ePrint 1212.3503
Jianxin Chen, Zhengfeng Ji, David W Kribs, Bei Zeng.
Minimum Entangling Power is Close to Its Maximum.
Also available as arXiv.org ePrint 1210.1296
Jianxin Chen, Andreas Winter.
NonAdditivity of the Entanglement of Purification (Beyond Reasonable Doubt).
Submitted.
Also available as arXiv.org ePrint 1206.1307
Presented at 12th Asian Quantum Information Science Conference, Suzhou, China, Aug. 2012.
Jianxin Chen, Zhengfeng Ji, David Kribs, Zhaohui Wei, Bei Zeng.
GroundState Spaces of FrustrationFree Hamiltonians.
Journal of Mathematical Physics, 53(10):102201, 2012
Also available as arXiv.org ePrint 1112.0762
Jianxin Chen, Zhengfeng Ji, Bei Zeng, Duanlu Zhou.
From Ground States to Local Hamiltonians.
Physical Review A, 86:022339, 2012.
Also available as arXiv.org ePrint 1110.6583
Jianxin Chen, Zhengfeng Ji, Mary Beth Ruskai, Bei Zeng, DuanLu Zhou.
Comment on some results of Erdahl and the convex structure of reduced density matrices.
Journal of Mathematical Physics, 53(7):072203, 2012.
Also available as arXiv.org ePrint 1205.3682
Jianxin Chen, Zhengfeng Ji, Zhaohui Wei, Bei Zeng.
Correlations in excited states of local Hamiltonians.
Physical Review A (rapid communication), 83:050301R, 2012.
Also available as arXiv.org ePrint 1106.1373
Jianxin Chen, Zhengfeng Ji, Alexander Klyachko, David Kribs, Bei Zeng.
Rank Reduction for Local Consistency Problem.
Journal of Mathematical Physics, 53(2):022202, 2012.
Also available as arXiv.org ePrint 1106.3235
Cheng Lu, Jianxin Chen, Runyao Duan.
Some Bounds on the Minimum Number of Queries Required for Quantum Channel Perfect Discrimination.
Quantum Information and Computation, 12(1&2):01380148, 2012.
A preliminary version titled Optimal Perfect Distinguishability between Unitaries and Quantum Operations is also available as arXiv.org eprint 1010.2298
Jianxin Chen, Toby Cubitt, Aram Harrow, Graeme Smith.
Entanglement Can Completely Defeat Quantum Noise.
Physical Review Letter (highlighted), 107:250504, Dec 2011. See accompanying Physics Synopsis
Also available as arXiv.org ePrint 1109.0540
Jianxin Chen, Xie Chen, Runyao Duan, Zhengfeng Ji, Bei Zeng.
NoGo Theorem for OneWay Quantum Computing on Naturally Occurring TwoLevel Systems.
Physical Review A (rapid communication), 83:050301R, 2011.
Also available as arXiv.org ePrint 1004.3787
Presented at 14th Workshop on Quantum Information Processing, The Capella, Sentosa Singapore, Jan. 2011.
Toby S. Cubitt, Jianxin Chen, Aram W. Harrow.
Superactivation of the Asymptotic ZeroError Classical Capacity of A Quantum Channel.
Information Theory, IEEE Transactions on, 57(12):81148126, 2011.
Also available as arXiv.org ePrint 0906.2547
Toby S. Cubitt, Jianxin Chen, Aram W. Harrow, Graeme Smith.
SuperDuperActivation of the ZeroError Quantum Capacity
Presented at Information Theory Proceedings (ISIT), 2010 IEEE International Symposium on, Austin, Texas, United States, Jun., 2010.
Also presented at 13th Workshop on Quantum Information Processing, Zurich, Switzerland, Jan. 2010.
Also presented at 10th Asian Quantum Information Science Conference , Tokyo, Japan, Aug. 2010.
Zhengfeng Ji, Jianxin Chen, Zhaohui Wei, Mingsheng Ying.
The LULC Conjecture is False.
Quantum Information and Computation, 10(1&2), 2010.
Also available as arXiv.org ePrint 0709.1266
Presented at The 11th Workshop on Quantum Information Processing, New Delhi, India, Dec. 2007.
Jianxin Chen, Mingsheng Ying.
AncillaAssisted Discrimination of Quantum Gates.
Quantum Information and Computation, 10(1&2), 2010.
Also available as arXiv.org ePrint 0809.0336
Jianxin Chen, Runyao Duan, Zhengfeng Ji, Mingsheng Ying, Jun Yu.
Existence of Universal Entangler.
Journal of Mathematical Physics, 49:012103, 2008.
Also available as arXiv.org ePrint 0704.1473
Mingsheng Ying, Jianxin Chen, Yuan Feng, Runyao Duan.
Commutativity of Quantum Weakest Preconditions.
Info. Proc. Lett., 104(4):152158, 2007.
Lirong Xia, Jianxin Chen, Xiaotong Zhang.
A Solution for Student Interview Problem (in Chinese),
Mathematics in Practice and Theory, 37(14):145, 2007.
Instructor: QIC 890 and 891: Module 4 Selected Advanced Topics in Quantum Information (Spring 2012), University of Waterloo
Teaching Assistant: Discrete Mathematics（Spring 2007), Tsinghua University
Teaching Assistant: Discrete Mathematics（Spring 2006), Tsinghua University
Postal Address Joint Center for Quantum Information and Computer Science, Telephone Cell: (240) 5428777 Office CSS2216 
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