Optimal dynamical control of many-body entanglement (2009)
Platzer, Felix, Mintert, Florian, Buchleitner, Andreas
The preparation of highly entangled many-body systems is one of the central challenges of both basic and applied science. The complexity of interparticle interaction and environment coupling...
Scattering laser light on cold atoms: multiple scattering signals from single-atom responses (2009)
Wellens, Thomas, Geiger, Tobias, Shatokhin, Vyacheslav, Buchleitner, Andreas
We deduce the coherent backscattering signal from two distant laser-driven atoms using single-atom equations. In contrast to the standard master equation treatment, this new approach is suitable for...
Equation of motion for entanglement (2009)
Tiersch, Markus, De Melo, Fernando, Konrad, Thomas, Buchleitner, Andreas
We review an evolution equation for quantum entanglement for 2x2 dimensional quantum systems, the smallest system that can exhibit entanglement, and extend it to higher dimensional systems....
Detection and typicality of bound entangled states (2009)
Bae, Joonwoo, Tiersch, Markus, Sauer, Simeon, De Melo, Fernando, Mintert, Florian, Hiesmayr, Beatrix, ...
We derive an explicit analytic estimate for the entanglement of a large class of bipartite quantum states which extends into bound entanglement regions. This is done by using a computable concurrence...
Entanglement of Identical Particles and the Detection Process (2009)
Tichy, Malte Christopher, De Melo, Fernando, Kuś, Marek, Mintert, Florian, Buchleitner, Andreas
While well understood for well separated particles, the entanglement of identical particles which overlap in space is hitherto a widely open problem. We introduce a unified entanglement concept for...
Scalability of GHZ and random-state entanglement in the presence of decoherence (2008)
Aolita, Leandro, Cavalcanti, Daniel, Acín, Antonio, Salles, Alejo, Tiersch, Markus, Buchleitner, Andreas, ...
We derive analytical upper bounds for the entanglement of generalized Greenberger-Horne-Zeilinger states coupled to locally depolarizing and dephasing environments, and for local thermal baths of...
Thermal non-equilibrium effects in quantum reflection (2008)
Druzhinina, Viola, Mudrich, Marcel, Arnecke, Florian, Madronero, Javier, Buchleitner, Andreas
We show that the quantum reflection coefficient of ultracold heavy atoms scattering off a dielectric surface can be tuned in a wide range by suitable choice of surface and environment temperatures....
Universality in open system entanglement dynamics (2008)
Tiersch, Markus, De Melo, Fernando, Buchleitner, Andreas
We show that the entanglement evolution of an open quantum system initially prepared in a random pure state - as quantified by a large class of entanglement quantifiers - is universal, in the limit...
Bose-Einstein condensation in an optical lattice: A perturbation approach (2008)
Trallero-Giner, C., Lopez-Richard, V., Chung, Ming-Chiang, Buchleitner, Andreas
We derive closed analytical expressions for the order parameter $\Phi (x)$ and for the chemical potential $\mu $ of a Bose-Einstein Condensate loaded into a harmonically confined, one dimensional...
Microwave driven atoms: from Anderson localization to Einstein's photo effect (2008)
Schelle, Alexej, Delande, Dominique, Buchleitner, Andreas
We study the counterpart of Anderson localization in driven one-electron Rydberg atoms. By changing the initial Rydberg state at fixed microwave frequency and interaction time, we numerically monitor...
Simulability and regularity of complex quantum systems (2008)
Venzl, Hannah, Daley, Andrew J., Mintert, Florian, Buchleitner, Andreas
We show that the transition from regular to chaotic spectral statistics in interacting many-body quantum systems has an unambiguous signature in the distribution of Schmidt coefficients dynamically...
Entanglement evolution in finite dimensions (2008)
Tiersch, Markus, De Melo, Fernando, Buchleitner, Andreas
We provide a relation which describes how the entanglement of two d-level systems evolves as either system undergoes an arbitrary physical process. The dynamics of the entanglement turns out to be of...
Experimental Direct Observation of Mixed State Entanglement (2008)
Schmid, Christian, Kiesel, Nikolai, Wieczorek, Witlef, Weinfurter, Harald, Mintert, Florian, Buchleitner, Andreas
Spectrum of coherently backscattered light from two atoms (2007)
Shatokhin, Vyacheslav, Wellens, Thomas, Grémaud, Benoît, Buchleitner, Andreas
We present a detailed analytical and numerical analysis of the inelastic coherent backscattering spectrum of laser light incident on cold atoms. We identify frequency domains where the interference...
Coherent backscattering of light from saturated atoms (2007)
Shatokhin, Vyacheslav, Wellens, Thomas, Müller, Cord, Buchleitner, Andreas
We survey recent progress achieved in understanding the impact of inelastic processes on coherent backscattering of light from cold atoms that are saturated by a powerful laser field.
Scalable experimental estimation of multipartite entanglement (2007)
Aolita, Leandro, Buchleitner, Andreas, Mintert, Florian
We present an efficient experimental estimation of the multipartite entanglement of mixed quantum states in terms of simple parity measurements.
A Factorization Law for Entanglement Decay (2007)
Konrad, Thomas, De Melo, Fernando, Tiersch, Markus, Kasztelan, Christian, Aragao, Adriano, Buchleitner, Andreas
We present a simple and general factorization law for quantum systems shared by two parties, which describes the time evolution of entanglement upon passage of either component through an arbitrary...
Entanglement-screening by nonlinear resonances (2007)
Garcia-Mata, Ignacio, Carvalho, Andre R. R., Mintert, Florian, Buchleitner, Andreas
We show that nonlinear resonances in a classically mixed phase space allow to define generic, strongly entangled multi-partite quantum states. The robustness of their multipartite entanglement...
Resonance-assisted decay of nondispersive wave packets (2006)
Wimberger, Sandro, Schlagheck, Peter, Eltschka, Christopher, Buchleitner, Andreas
We present a quantitative semiclassical theory for the decay of nondispersive electronic wave packets in driven, ionizing Rydberg systems. Statistically robust quantities are extracted combining...
Demkowicz-Dobrzanski, Rafal, Buchleitner, Andreas, Kus, Marek, Mintert, Florian
We discuss the monotonicity under local operations and classical communication (LOCC) of systematically constructed quantities aiming at quantification of entanglement properties of multipartite...
An observable entanglement measure for unknown mixed quantum states (2006)
Mintert, Florian, Buchleitner, Andreas
We show how an unknown mixed quantum state's entanglement can be quantified by a suitable, local parity measurement on its two-fold copy.
Saturation of fidelity in the atom-optics kicked rotor (2006)
Wimberger, Sandro, Buchleitner, Andreas
We show that the quantum fidelity is accessible to cold atom experiments for a large class of evolutions in periodical potentials, properly taking into account the experimental initial conditions of...
Atomes de Rydberg en champ micro-onde : régularité et chaos (2006)
Nous développons un formalisme théorique qui fournit un outil puissant pour l'analyse numérique détaillée de l'interaction d'un atome d'hydrogène tridimensionnel avec un champ de rayonnement...
Shatokhin, Vyacheslav, Müller, Cord A., Buchleitner, Andreas
We give a detailed derivation of the master equation description of the coherent backscattering of laser light by cold atoms. In particular, our formalism accounts for the nonperturbative nonlinear...
Resonance-Assisted Decay of Nondispersive Wave Packets (2006)
Wimberger, Sandro, Schlagheck, Peter, Eltschka, Christopher, Buchleitner, Andreas
We present a quantitative semiclassical theory for the decay of nondispersive electronic wave packets in driven, ionizing Rydberg systems. Statistically robust quantities are extracted combining...
Unravelling Entanglement (2005)
Carvalho, André R. R., Busse, Marc, Brodier, Olivier, Viviescas, Carlos, Buchleitner, Andreas
We show that the time evolution of entanglement under incoherent environment coupling can be faithfully recovered by monitoring the system according to a suitable measurement scheme.
Atomic current across an optical lattice (2005)
Ponomarev, Alexey V., Madronero, Javier, Kolovsky, Andrey R., Buchleitner, Andreas
We devise a microscopic model for the emergence of a collision-induced, fermionic atomic current across a tilted optical lattice. Tuning the - experimentally controllable - parameters of the...
Entanglement dynamics under decoherence: from qubits to qudits (2005)
Carvalho, André R. R., Mintert, Florian, Palzer, Stefan, Buchleitner, Andreas
We investigate the time evolution of entanglement for bipartite systems of arbitrary dimensions under the influence of decoherence. For qubits, we determine the precise entanglement decay rates under...
Nonlinearity induced destruction of resonant tunneling in the Wannier-Stark problem (2005)
Wimberger, Sandro, Mannella, Riccardo, Morsch, Oliver, Arimondo, Ennio, Kolovsky, Andrey, Buchleitner, Andreas
We present detailed numerical results on the dynamics of a Bose-Einstein condensate in a tilted periodic optical lattice over many Bloch periods. We show that an increasing atom-atom interaction...
Measures and dynamics of entangled states (2005)
Mintert, Florian, Carvalho, Andre R. R., Kus, Marek, Buchleitner, Andreas
We develop an original approach for the quantitative characterisation of the entanglement properties of, possibly mixed, bi- and multipartite quantum states of arbitrary finite dimension. Particular...
Concurrence of mixed multi-partite quantum states (2004)
Mintert, Florian, Kus, Marek, Buchleitner, Andreas
We propose generalizations of concurrence for multi-partite quantum systems that can distinguish qualitatively distinct quantum correlations. All introduced quantities can be evaluated efficiently...
Concurrence of quasi pure quantum states (2004)
Mintert, Florian, Buchleitner, Andreas
We derive an analytic approximation for the concurrence of weakly mixed bipartite quantum states - typical objects in state of the art experiments. This approximation is shown to be a lower bound of...
Decoherence and multipartite entanglement (2004)
Carvalho, André R. R., Mintert, Florian, Buchleitner, Andreas
We study the dynamics of multipartite entanglement under the influence of decoherence. A suitable generalization of concurrence reveals distinct scaling of the entanglement decay rate of GHZ and W...
Web-assisted tunneling in the kicked harmonic oscillator (2004)
Carvalho, André R. R., Buchleitner, Andreas
We show that heating of harmonically trapped ions by periodic delta kicks is dramatically enhanced at isolated values of the Lamb-Dicke parameter. At these values, quasienergy eigenstates localized...
A universal ionization threshold for strongly driven Rydberg states (2004)
Krug, Andreas, Buchleitner, Andreas
We observe a universal ionization threshold for microwave driven one-electron Rydberg states of H, Li, Na, and Rb, in an {\em ab initio} numerical treatment without adjustable parameters. This sheds...
Quantum Chaos in the Bose-Hubbard model (2004)
Kolovsky, Andrey R., Buchleitner, Andreas
We present a numerical study of the spectral properties of the 1D Bose-Hubbard model. Unlike the 1D Hubbard model for fermions, this system is found to be non-integrable, and exhibits Wigner-Dyson...
Concurrence of mixed bipartite quantum states in arbitrary dimensions (2004)
Mintert, Florian, Kus, Marek, Buchleitner, Andreas
We derive a lower bound for the concurrence of mixed bipartite quantum states, valid in arbitrary dimensions. As a corollary, a weaker, purely algebraic estimate is found, which detects mixed...
Multi-particle quantum chaos in tilted optical lattices (2003)
Kolovsky, Andrey R., Buchleitner, Andreas
We show that, in the parameter regime of state of the art experiments on Bose Einstein Condensates loaded into optical lattices, the energy spectrum of the 1D Bose-Hubbard model amended by a static...
Decoherence as a Probe of Coherent Quantum Dynamics (2003)
D'Arcy, Michael B., Godun, Rachel M., Summy, Gil S., Guarneri, Italo, Wimberger, Sandro, Fishman, Shmuel, ...
The effect of decoherence, induced by spontaneous emission, on the dynamics of cold atoms periodically kicked by an optical lattice is experimentally and theoretically studied. Ideally, the mean...
Entanglement of 2xK quantum systems (2003)
Lozinski, Artur, Buchleitner, Andreas, Zyczkowski, Karol, Wellens, Thomas
We derive an analytical expression for the lower bound of the concurrence of mixed quantum states of composite 2xK systems. In contrast to other, implicitly defined entanglement measures, the...
Nondispersive two-electron wave packets in driven helium (2003)
Schlagheck, Peter, Buchleitner, Andreas
We provide a detailed quantum treatment of the spectral characteristics and of the dynamics of nondispersive two-electron wave packets along the periodically driven, collinear frozen planet...
Decay Rates and Survival Probabilities in Open Quantum Systems (2002)
Wimberger, Sandro, Krug, Andreas, Buchleitner, Andreas
We provide the first statistical analysis of the decay rates of strongly driven 3D atomic Rydberg states. The distribution of the rates exhibits universal features due to Anderson localization, while...
Decay, interference, and chaos: How simple atoms mimic disorder (2002)
Krug, Andreas, Wimberger, Sandro, Buchleitner, Andreas
We establish a close quantitative analogy between the excitation and ionization process of highly excited one electron Rydberg states under microwave driving and charge transport across disordered 1D...
Nondispersive two-electron wave packets in driven helium (2002)
Schlagheck, Peter, Buchleitner, Andreas
We provide a detailed quantum treatment of the spectral characteristics and of the dynamics of nondispersive two-electron wave packets along the periodically driven, collinear frozen planet...
Anderson Localization in Atoms (2002)
Wimberger, Sandro, Buchleitner, Andreas
A statistical analysis of the ionization yield of one-dimensional, periodically driven hydrogen Rydberg states is provided. We find excellent agreement with predictions for the conductance across an...
Wimberger, Sandro, Buchleitner, Andreas
We provide a statistical characterization of the ionization yield of one-dimensional, periodically driven Rydberg states of atomic hydrogen, in the spirit of Anderson localization theory. We find...
Non-dispersive wave packets in periodically driven quantum systems (2002)
Buchleitner, Andreas, Delande, Dominique, Zakrzewski, Jakub
With the exception of the harmonic oscillator, quantum wave-packets usually spread as time evolves. We show here that, using the nonlinear resonance between an internal frequency of a system and an...
Krug,Andreas, Buchleitner,Andreas
We report on a novel numerical treatment of highly excited alkali Rydberg states strongly driven by a coherent microwave field. Our approach establishes particularly clean experimental conditions...
Krug, Andreas, Buchleitner, Andreas
We report on a novel numerical treatment of highly excited alkali Rydberg states strongly driven by a coherent microwave field. Our approach establishes particularly clean experimental conditions...
Residual Symmetries in the Spectrum of Periodically Driven Alkali Rydberg States (1999)
Krug, Andreas, Buchleitner, Andreas
We identify a fundamental structure in the spectrum of microwave driven alkali Rydberg states, which highlights the remnants of the Coulomb symmetry in the presence of a non-hydrogenic core....
Ionization via Chaos Assisted Tunneling (1997)
Zakrzewski, Jakub, Delande, Dominique, Buchleitner, Andreas
A simple example of quantum transport in a classically chaotic system is studied. It consists in a single state lying on a regular island (a stable primary resonance island) which may tunnel into a...
Wavefunctions of atomic resonances (1994)
Buchleitner, Andreas, Grémaud, Benoit, Delande, Dominique
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Atomes de Rydberg en champ micro-onde : régularité et chaos (1993)
Nous développons un formalisme théorique qui fournit un outil puissant pour l'analyse numérique détaillée de l'interaction d'un atome d'hydrogène tridimensionnel avec un champ de rayonnement...
Atomes de Rydberg en champ micro-onde : régularité et chaos (1993)
Nous développons un formalisme théorique qui fournit un outil puissant pour l'analyse numérique détaillée de l'interaction d'un atome d'hydrogène tridimensionnel avec un champ de rayonnement...
Atomes de Rydberg en champ micro-onde : régularité et chaos (1993)
Nous développons un formalisme théorique qui fournit un outil puissant pour l'analyse numérique détaillée de l'interaction d'un atome d'hydrogène tridimensionnel avec un champ de rayonnement...
Atomes de Rydberg en champ micro-onde : régularité et chaos (1993)
Nous développons un formalisme théorique qui fournit un outil puissant pour l'analyse numérique détaillée de l'interaction d'un atome d'hydrogène tridimensionnel avec un champ de rayonnement...
Atomes de Rydberg en champ micro-onde : régularité et chaos (1993)
Nous développons un formalisme théorique qui fournit un outil puissant pour l'analyse numérique détaillée de l'interaction d'un atome d'hydrogène tridimensionnel avec un champ de rayonnement...
Quantum dynamics of a circular Rydberg state in a microwave field (1993)
Buchleitner, Andreas, Delande, Dominique
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Dynamical localization in more than one dimension (1993)
Buchleitner, Andreas, Delande, Dominique
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Rubidium Rydberg atoms in bichromatic microwave fields (1991)
Buchleitner, Andreas, Sirko, Leszek, Walther, Herbert
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