@misc{RaederEisertWilkensetal.2005,
  author    = {R{\"a}der, Andy and Eisert, Jens and Wilkens, Martin and Schmidt, Robert and Micka, Bettina and Ostermeyer, Martin and Zill, R{\"u}diger and Baur, J{\"u}rgen and Schmidt, Renate and Leppin, Karin and Slotowski, Agnes and Resch-Esser, Ursula},
  title     = {Portal = Albert Einsteins Erbe: Uni-Physiker forschen weiter},
  number    = {01-03/2005},
  organization    = {Universit{\"a}t Potsdam, Referat f{\"u}r Presse- und {\"O}ffentlichkeitsarbeit},
  issn      = {1618-6893},
  doi       = {10.25932/publishup-43984},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-439846},
  pages     = {55},
  year      = {2005},
  abstract  = {Aus dem Inhalt: - Albert Einsteins Erbe: Uni-Physiker forschen weiter - Uni-Studiengang im europ{\"a}ischen Exzellenzprogramm - Sternenstaubsammler - Mit Einfallsreichtum gegen den Trend},
  language  = {de}
}
@article{LemrCernochSoubustaetal.2011,
  author    = {Lemr, Karel and Cernoch, A. and Soubusta, Jan and Kieling, Konrad and Eisert, Jens and Dusek, M.},
  title     = {Experimental implementation of the optimal linear-optical controlled phase gate},
  series = {Physical review letters},
  volume    = {106},
  journal   = {Physical review letters},
  number    = {1},
  publisher = {American Physical Society},
  address   = {College Park},
  issn      = {0031-9007},
  doi       = {10.1103/PhysRevLett.106.013602},
  pages     = {4},
  year      = {2011},
  abstract  = {We report on the first experimental realization of optimal linear-optical controlled phase gates for arbitrary phases. The realized scheme is entirely flexible in that the phase shift can be tuned to any given value. All such controlled phase gates are optimal in the sense that they operate at the maximum possible success probabilities that are achievable within the framework of postselected linear-optical implementations with vacuum ancillas. The quantum gate is implemented by using bulk optical elements and polarization encoding of qubit states. We have experimentally explored the remarkable observation that the optimum success probability is not monotone in the phase.},
  language  = {en}
}
@article{MariKielingNielsenetal.2011,
  author    = {Mari, Andrea and Kieling, Konrad and Nielsen, B. Melholt and Polzik, E. S. and Eisert, Jens},
  title     = {Directly estimating nonclassicality},
  series = {Physical review letters},
  volume    = {106},
  journal   = {Physical review letters},
  number    = {1},
  publisher = {American Physical Society},
  address   = {College Park},
  issn      = {0031-9007},
  doi       = {10.1103/PhysRevLett.106.010403},
  pages     = {4},
  year      = {2011},
  abstract  = {We establish a method of directly measuring and estimating nonclassicality-operationally defined in terms of the distinguishability of a given state from one with a positive Wigner function. It allows us to certify nonclassicality, based on possibly much fewer measurement settings than necessary for obtaining complete tomographic knowledge, and is at the same time equipped with a full certificate. We find that even from measuring two conjugate variables alone, one may infer the nonclassicality of quantum mechanical modes. This method also provides a practical tool to eventually certify such features in mechanical degrees of freedom in opto-mechanics. The proof of the result is based on Bochner's theorem characterizing classical and quantum characteristic functions and on semidefinite programming. In this joint theoretical-experimental work we present data from experimental optical Fock state preparation.},
  language  = {en}
}
@article{GogolinMuellerEisert2011,
  author    = {Gogolin, Christian and M{\"u}ller, Markus P. and Eisert, Jens},
  title     = {Absence of thermalization in nonintegrable systems},
  series = {Physical review letters},
  volume    = {106},
  journal   = {Physical review letters},
  number    = {4},
  publisher = {American Physical Society},
  address   = {College Park},
  issn      = {0031-9007},
  doi       = {10.1103/PhysRevLett.106.040401},
  pages     = {4},
  year      = {2011},
  abstract  = {We establish a link between unitary relaxation dynamics after a quench in closed many-body systems and the entanglement in the energy eigenbasis. We find that even if reduced states equilibrate, they can have memory on the initial conditions even in certain models that are far from integrable. We show that in such situations the equilibrium states are still described by a maximum entropy or generalized Gibbs ensemble, regardless of whether a model is integrable or not, thereby contributing to a recent debate. In addition, we discuss individual aspects of the thermalization process, comment on the role of Anderson localization, and collect and compare different notions of integrability.},
  language  = {en}
}
@article{MuellerGrossEisert2011,
  author    = {M{\"u}ller, Markus P. and Gross, David and Eisert, Jens},
  title     = {Concentration of Measure for Quantum States with a Fixed Expectation Value},
  series = {Communications in mathematical physics},
  volume    = {303},
  journal   = {Communications in mathematical physics},
  number    = {3},
  publisher = {Springer},
  address   = {New York},
  issn      = {0010-3616},
  doi       = {10.1007/s00220-011-1205-1},
  pages     = {785 -- 824},
  year      = {2011},
  abstract  = {Given some observable H on a finite-dimensional quantum system, we investigate the typical properties of random state vectors vertical bar psi >> that have a fixed expectation value < psi vertical bar H vertical bar psi > = E with respect to H. Under some conditions on the spectrum, we prove that this manifold of quantum states shows a concentration of measure phenomenon: any continuous function on this set is almost everywhere close to its mean. We also give a method to estimate the corresponding expectation values analytically, and we prove a formula for the typical reduced density matrix in the case that H is a sum of local observables. We discuss the implications of our results as new proof tools in quantum information theory and to study phenomena in quantum statistical mechanics. As a by-product, we derive a method to sample the resulting distribution numerically, which generalizes the well-known Gaussian method to draw random states from the sphere.},
  language  = {en}
}
@article{BrandaoEisertHorodeckietal.2011,
  author    = {Brandao, F. G. S. L. and Eisert, Jens and Horodecki, M. and Yang, Dong},
  title     = {Entangled inputs cannot make imperfect quantum channels perfect},
  series = {Physical review letters},
  volume    = {106},
  journal   = {Physical review letters},
  number    = {23},
  publisher = {American Physical Society},
  address   = {College Park},
  issn      = {0031-9007},
  doi       = {10.1103/PhysRevLett.106.230502},
  pages     = {4},
  year      = {2011},
  abstract  = {Entangled inputs can enhance the capacity of quantum channels, this being one of the consequences of the celebrated result showing the nonadditivity of several quantities relevant for quantum information science. In this work, we answer the converse question (whether entangled inputs can ever render noisy quantum channels to have maximum capacity) to the negative: No sophisticated entangled input of any quantum channel can ever enhance the capacity to the maximum possible value, a result that holds true for all channels both for the classical as well as the quantum capacity. This result can hence be seen as a bound as to how "nonadditive quantum information can be.'' As a main result, we find first practical and remarkably simple computable single-shot bounds to capacities, related to entanglement measures. As examples, we discuss the qubit amplitude damping and identify the first meaningful bound for its classical capacity.},
  language  = {en}
}
@article{HuebenerKruszynskaHartmannetal.2011,
  author    = {H{\"u}bener, Robert and Kruszynska, Caroline and Hartmann, Lorenz and Duer, Wolfgang and Plenio, Martin B. and Eisert, Jens},
  title     = {Tensor network methods with graph enhancement},
  series = {Physical review : B, Condensed matter and materials physics},
  volume    = {84},
  journal   = {Physical review : B, Condensed matter and materials physics},
  number    = {12},
  publisher = {American Physical Society},
  address   = {College Park},
  issn      = {1098-0121},
  doi       = {10.1103/PhysRevB.84.125103},
  pages     = {24},
  year      = {2011},
  abstract  = {We present applications of the renormalization algorithm with graph enhancement (RAGE). This analysis extends the algorithms and applications given for approaches based on matrix product states introduced in [Phys. Rev. A 79, 022317 (2009)] to other tensor-network states such as the tensor tree states (TTS) and projected entangled pair states. We investigate the suitability of the bare TTS to describe ground states, showing that the description of certain graph states and condensed-matter models improves. We investigate graph-enhanced tensor-network states, demonstrating that in some cases (disturbed graph states and for certain quantum circuits) the combination of weighted graph states with TTS can greatly improve the accuracy of the description of ground states and time-evolved states. We comment on delineating the boundary of the classically efficiently simulatable states of quantum many-body systems.},
  language  = {en}
}
@article{SchuchHarrisonOsborneetal.2011,
  author    = {Schuch, Norbert and Harrison, Sarah K. and Osborne, Tobias J. and Eisert, Jens},
  title     = {Information propagation for interacting-particle systems},
  series = {Physical review : A, Atomic, molecular, and optical physics},
  volume    = {84},
  journal   = {Physical review : A, Atomic, molecular, and optical physics},
  number    = {3},
  publisher = {American Physical Society},
  address   = {College Park},
  issn      = {1050-2947},
  doi       = {10.1103/PhysRevA.84.032309},
  pages     = {5},
  year      = {2011},
  abstract  = {We study the speed at which information propagates through systems of interacting quantum particles moving on a regular lattice and show that for a certain class of initial conditions there exists a maximum speed of sound at which information can propagate. Our argument applies equally to quantum spins, bosons such as in the Bose-Hubbard model, fermions, anyons, and general mixtures thereof, on arbitrary lattices of any dimension. It also pertains to dissipative dynamics on the lattice, and generalizes to the continuum for quantum fields. Our result can be seen as an analog of the Lieb-Robinson bound for strongly correlated models.},
  language  = {en}
}
@article{DiGuglielmoSamblowskiHageetal.2011,
  author    = {DiGuglielmo, J. and Samblowski, A. and Hage, B. and Pineda, Carlos and Eisert, Jens and Schnabel, R.},
  title     = {Experimental Unconditional Preparation and Detection of a Continuous Bound Entangled State of Light},
  series = {Physical review letters},
  volume    = {107},
  journal   = {Physical review letters},
  number    = {24},
  publisher = {American Physical Society},
  address   = {College Park},
  issn      = {0031-9007},
  doi       = {10.1103/PhysRevLett.107.240503},
  pages     = {5},
  year      = {2011},
  abstract  = {Among the possibly most intriguing aspects of quantum entanglement is that it comes in free and bound instances. The existence of bound entangled states certifies an intrinsic irreversibility of entanglement in nature and suggests a connection with thermodynamics. In this Letter, we present a first unconditional, continuous-variable preparation and detection of a bound entangled state of light. We use convex optimization to identify regimes rendering its bound character well certifiable, and continuously produce a distributed bound entangled state with an extraordinary and unprecedented significance of more than 10 standard deviations away from both separability and distillability. Our results show that the approach chosen allows for the efficient and precise preparation of multimode entangled states of light with various applications in quantum information, quantum state engineering, and high precision metrology.},
  language  = {en}
}
@article{CampbellEisert2012,
  author    = {Campbell, Earl T. and Eisert, Jens},
  title     = {Gaussification and entanglement distillation of continuous-variable systems a unifying picture},
  series = {Physical review letters},
  volume    = {108},
  journal   = {Physical review letters},
  number    = {2},
  publisher = {American Physical Society},
  address   = {College Park},
  issn      = {0031-9007},
  doi       = {10.1103/PhysRevLett.108.020501},
  pages     = {5},
  year      = {2012},
  abstract  = {Distillation of entanglement using only Gaussian operations is an important primitive in quantum communication, quantum repeater architectures, and distributed quantum computing. Existing distillation protocols for continuous degrees of freedom are only known to converge to a Gaussian state when measurements yield precisely the vacuum outcome. In sharp contrast, non-Gaussian states can be deterministically converted into Gaussian states while preserving their second moments, albeit by usually reducing their degree of entanglement. In this work-based on a novel instance of a noncommutative central limit theorem-we introduce a picture general enough to encompass the known protocols leading to Gaussian states, and new classes of protocols including multipartite distillation. This gives the experimental option of balancing the merits of success probability against entanglement produced.},
  language  = {en}
}