Resource-Efficient Measurement-Device-Independent Entanglement Witness.

Imperfections in experimental measurement schemes can lead to falsely identifying, or over estimating, entanglement in a quantum system. A recent solution to this is to define schemes that are robust to measurement imperfections-measurement-device-independent entanglement witness (MDI-EW). This approach can be adapted to witness all entangled qubit states for a wide range of physical systems and does not depend on detection efficiencies or classical communication between devices. Here we extend the theory to remove the necessity of prior knowledge about the two-qubit states to be witnessed. Moreover, we tested this model via a novel experimental implementation for MDI-EW that significantly reduces the experimental complexity. By applying it to a bipartite Werner state, we demonstrate the robustness of this approach against noise by witnessing entanglement down to an entangled state fraction close to 0.4.

[1]  Todd A. Brun,et al.  Quantum Computing , 2011, Computer Science, The Hardware, Software and Heart of It.

[2]  G. Tóth,et al.  Entanglement detection , 2008, 0811.2803.

[3]  Nicolas Gisin,et al.  Quantum repeaters based on atomic ensembles and linear optics , 2009, 0906.2699.

[4]  F. Nori,et al.  Quantum Simulation , 2013, Quantum Atom Optics.

[5]  Xiongfeng Ma,et al.  Reliable and robust entanglement witness , 2015, 1512.02352.

[6]  Jean-Daniel Bancal,et al.  Device-independent entanglement quantification and related applications. , 2013, Physical review letters.

[7]  Mohamed Bourennane,et al.  Experimental Measurement-Device-Independent Entanglement Detection , 2015, Scientific Reports.

[8]  Zach DeVito,et al.  Opt , 2017 .

[9]  Stephen P. Boyd,et al.  Convex Optimization , 2004, Algorithms and Theory of Computation Handbook.

[10]  J. Bell.  On the Einstein-Podolsky-Rosen paradox , 1964 .

[11]  Peter Hawkes,et al.  Advances in Imaging and Electron Physics , 2002 .

[12]  W. Munro,et al.  Qudit quantum-state tomography , 2002 .

[13]  Nicolas Gisin,et al.  Quantum communication , 2017, 2017 Optical Fiber Communications Conference and Exhibition (OFC).

[14]  Andrew G. Glen,et al.  APPL , 2001 .

[15]  R. Thew,et al.  Simple, pulsed, polarization entangled photon pair source , 2013, 1311.6654.

[16]  Kerry Vahala,et al.  Cavity opto-mechanics. , 2007, Optics express.

[17]  Francesco Buscemi,et al.  All entangled quantum states are nonlocal. , 2011, Physical review letters.

[18]  Nicolas Gisin,et al.  Entangled states cannot be classically simulated in generalized Bell experiments with quantum inputs , 2013 .

[19]  Kaushik P. Seshadreesan,et al.  Quantum Optical Technologies for Metrology, Sensing, and Imaging , 2014, Journal of Lightwave Technology.

[20]  Hermann Kampermann,et al.  Entanglement witnesses and a loophole problem , 2007 .

[21]  M. Genovese.  Research on hidden variable theories: A review of recent progresses , 2005, quant-ph/0701071.

[22]  C. Lim.  Optimality of semiquantum nonlocality in the presence of high inconclusive rates , 2015, 1511.00531.

[23]  A. Sørensen,et al.  Quantum interface between light and atomic ensembles , 2008, 0807.3358.

[24]  Ping Xu,et al.  Implementation of a measurement-device-independent entanglement witness. , 2014, Physical review letters.

[25]  C. Schwemmer,et al.  Systematic errors in current quantum state tomography tools. , 2013, Physical review letters.

[26]  Rob Thew,et al.  Detector-device-independent quantum key distribution , 2014, 1410.1850.

[27]  Andrew G. White,et al.  Measurement of qubits , 2001, quant-ph/0103121.

[28]  L. A. Ngah,et al.  High-quality polarization entanglement state preparation and manipulation in standard telecommunication channels , 2012, 1206.3809.

[29]  Jos F. Sturm,et al.  A Matlab toolbox for optimization over symmetric cones , 1999 .

[30]  M. Horodecki,et al.  Separability of mixed states: necessary and sufficient conditions , 1996, quant-ph/9605038.

[31]  Laura Mančinska,et al.  Everything You Always Wanted to Know About LOCC (But Were Afraid to Ask) , 2012, 1210.4583.

[32]  W. Marsden.  I and J , 2012 .

[33]  N. Gisin,et al.  From Bell's theorem to secure quantum key distribution. , 2005, Physical review letters.

[34]  Nicolas Gisin,et al.  Measurement-device-independent entanglement witnesses for all entangled quantum states. , 2012, Physical review letters.