Asymptotic Evolution of Random Unitary Operations (2009)
Novotny, J., Alber, G., Jex, I.
We analyze the asymptotic dynamics of quantum systems resulting from large numbers of iterations of random unitary operations. Although, in general, these quantum operations cannot be diagonalized it...
Random unitary dynamics of quantum networks (2009)
Novotny, J., Alber, G., Jex, I.
We investigate the asymptotic dynamics of quantum networks under repeated applications of random unitary operations. It is shown that in the asymptotic limit of large numbers of iterations this...
Tag der mündlichen Prüfung: 13.03.2006 (2008)
Den Naturwissenschaftlichen Fakultäten, Curty Alonso, Vorsitzender Promotionskommission, Prof Dr, ...
vorgelegt von
Manipulating sudden death of entanglement of two-qubit X-states in thermal reservoirs (2008)
Ali, Mazhar, Alber, G., Rau, A. R. P.
Manipulation of sudden death of entanglement (ESD) of two qubits interacting with statistically uncorrelated thermal reservoirs is investigated. It is shown that for initially prepared X-states of...
Locality, detection efficiencies, and probability polytopes (2008)
Wilms, J., Disser, Y., Alber, G., Percival, I. C.
We present a detailed investigation of minimum detection efficiencies, below which locality cannot be violated by any quantum system of any dimension in bipartite Bell experiments. Lower bounds on...
Schulz, S.M., Köhler, G., Schütze, N., Knauer, J., Straubinger, R.K., Chackerian, A.A., ...
IL-12 is essential for protective T cell-mediated immunity against Salmonella infection. To characterize the role of the related cytokine IL-23, wild-type (WT) C57BL/6 and p19 -/-mice were infected...
Dynamics of electronic Rydberg wave packets in the presence of laser-induced core transitions (2007)
Recent theoretical work on the dynamics of electronic Rydberg wave packets under the influence of laser-induced core transitions is reviewed. The discussion focuses on the intricate interplay between...
: It is shown that di#usion and stochastic ionization of an optically excited Rydberg electron are generic long time phenomena which are consequences of the destruction of quantum coherence by laser...
Hastening, delaying, or averting sudden death of quantum entanglement (2007)
Rau, A. R. P., Ali, Mazhar, Alber, G.
The finite time end of entanglement between two decohering qubits can be modified by local, unitary actions performed during the decohering process. Depending on the time when such action is taken,...
Complex chaos in conditional qubit dynamics and purification protocols (2007)
Kiss, T., Jex, I., Alber, G., Vymetal, S.
Selection of an ensemble of equally prepared quantum systems, based on measurements on it, is a basic step in quantum state purification. For an ensemble of single qubits, iterative application of...
Quantum error correction of coherent errors by randomization (2007)
Kern, O., Alber, G., Shepelyansky, D. L.
A general error correction method is presented which is capable of correcting coherent errors originating from static residual inter-qubit couplings in a quantum computer. It is based on a...
Network implementation of covariant two-qubit quantum operations (2007)
Novotny, J., Alber, G., Jex, I.
A six-qubit quantum network consisting of conditional unitary gates is presented which is capable of implementing a large class of covariant two-qubit quantum operations. Optimal covariant NOT...
Verfahren zum Schneiden von zu fuegenden Bauteilen mit Laserstrahlung (2007)
Schulz, W., Michel, J., Abels, P., Alber, G., Neubert, J., Behr, F., ...
WO 200272304 A UPAB: 20021022 NOVELTY - The cutting method has a computer-controlled handling system for the laser cutting beam, for guiding it along a defined cutting path corresponding to a curved...
Novotny, J., Alber, G., Jex, I.
The structure of all completely positive quantum operations is investigated which transform pure two-qubit input states of a given degree of entanglement in a covariant way. Special cases thereof are...
Selective recoupling and stochastic dynamical decoupling (2006)
An embedded selective recoupling method is proposed which is based on the idea of embedding the recently proposed deterministic selective recoupling scheme of Yamaguchi et al. [quant-ph/0411099] into...
Complex chaos in the conditional dynamics of qubits (2005)
Kiss, T., Jex, I., Alber, G., Vymetal, S.
We analyze the consequences of iterative measurement-induced nonlinearity on the dynamical behavior of qubits. We present a one-qubit scheme where the equation governing the time evolution is a...
Provable entanglement and information cost for qubit-based quantum key-distribution protocols (2005)
Nikolopoulos, G. M., Khalique, A., Alber, G.
Provable entanglement has been shown to be a necessary precondition for unconditionally secure key generation in the context of quantum cryptographic protocols. We estimate the maximal threshold...
Optimal copying of entangled two-qubit states (2004)
Novotny, J., Alber, G., Jex, I.
We investigate the problem of copying pure two-qubit states of a given degree of entanglement in an optimal way. Completely positive covariant quantum operations are constructed which maximize the...
Quantum error correction of coherent errors by randomization (2004)
Kern, O., Alber, G., Shepelyansky, D. L.
A general error correction method is presented which is capable of correcting coherent errors originating from static residual inter-qubit couplings in a quantum computer. It is based on a...
Metikas, G., Zobay, O., Alber, G.
We discuss the application of the momentum-shell renormalization group method to the interacting homogeneous Bose gas in the symmetric and in the symmetry-broken phases. It is demonstrated that...
Thermodynamics of a trapped interacting Bose gas and the renormalization group (2003)
Metikas, G., Zobay, O., Alber, G.
We apply perturbative renormalization group theory to the symmetric phase of a dilute interacting Bose gas which is trapped in a three-dimensional harmonic potential. Using Wilsonian energy-shell...
Antisymmetric multi-partite quantum states and their applications (2003)
Jex, I., Alber, G., Barnett, S.M.*, Delgado, A.
Entanglement is a powerful resource for processing quantum information. In this context pure, maximally entangled states have received considerable attention. In the case of bipartite qubit-systems...
Antisymmetric multi-partite quantum states and their applications (2003)
Jex, I., Alber, G., Barnett, S.M., Delgado, A.
Entanglement is a powerful resource for processing quantum information. In this context pure, maximally entangled states have received considerable attention. In the case of bipartite qubit-systems...
Antisymmetric multi-partite quantum states and their applications (2003)
Jex, I., Alber, G., Barnett, S.M., Delgado, A.
Entanglement is a powerful resource for processing quantum information. In this context pure, maximally entangled states have received considerable attention. In the case of bipartite qubit-systems...
Detected-jump-error correcting quantum codes, quantum error designs and quantum computation (2003)
Alber, G, Beth, Th, Charnes, Ch, Delgado, A, Grassl, M, Mussinger, M
The recently introduced detected-jump-correcting quantum codes are capable of stabilizing qubit systems against spontaneous decay processes arising from couplings to statistically independent...
Detected-jump-error correcting quantum codes, quantum error designs and quantum computation (2003)
Alber, G, Beth, Th, Charnes, Ch, Delgado, A, Grassl, M, Mussinger, M
The recently introduced detected-jump-correcting quantum codes are capable of stabilizing qubit systems against spontaneous decay processes arising from couplings to statistically independent...
Antisymmetric multi-partite quantum states and their applications (2002)
Jex, I., Alber, G., Barnett, S. M., Delgado, A.
Entanglement is a powerful resource for processing quantum information. In this context pure, maximally entangled states have received considerable attention. In the case of bipartite qubit-systems...
Universal Sets of Quantum Gates for Detected Jump-Error Correcting Quantum Codes (2002)
Alber, G., Mussinger, M., Delgado, A.
A universal set of quantum gates is constructed for the recently developed jump-error correcting quantum codes. These quantum codes are capable of correcting errors arising from the spontaneous decay...
Detected jump-error correcting quantum codes, quantum error designs and quantum computation (2002)
Alber, G., Beth, Th., Charnes, Ch., Delgado, A., Grassl, M., Mussinger, M.
The recently introduced detected-jump correcting quantum codes are capable of stabilizing qubit-systems against spontaneous decay processes arising from couplings to statistically independent...
Alber, G., Beth, Th., Charnes, Ch., Delgado, A., Grassl, M., Mussinger, M.
A new class of error-correcting quantum codes is introduced capable of stabilizing qubits against spontaneous decay arising from couplings to statistically independent reservoirs. These quantum codes...
Alber, G, Beth, Th, Charnes, Ch, Delgado, A, Grassl, M, Mussinger, M
A new class of error-correcting quantum codes is introduced capable of stabilizing qubits against spontaneous decay arising from couplings to statistically independent reservoirs. These quantum codes...
Alber, G, Beth, Th, Charnes, Ch, Delgado, A, Grassl, M, Mussinger, M
A new class of error-correcting quantum codes is introduced capable of stabilizing qubits against spontaneous decay arising from couplings to statistically independent reservoirs. These quantum codes...
Renormalization Group Analysis Of A Confined, Interacting Bose Gas (2001)
The renormalization group is not only a powerful method for describing universal properties of phase transitions but it is also useful for evaluating non-universal thermodynamic properties beyond...
A renormalization group method is developed with which thermodynamic properties of a weakly interacting, confined Bose gas can be investigated. Thereby effects originating from a confining potential...
Optimal universal two-particle entanglement processes in arbitrary dimensional Hilbert spaces (2000)
Alber, G., Delgado, A., Jex, I.
Universal two-particle entanglement processes are analyzed in arbitrary dimensional Hilbert spaces. On the basis of this analysis the class of possible optimal universal entanglement processes is...
Quantum Revivals in a Periodically Driven Gravitational Cavity (2000)
Saif, F., Alber, G., Savichev, V., Schleich, W. P.
Quantum revivals are investigated for the dynamics of an atom in a driven gravitational cavity. It is demonstrated that the external driving field influences the revival time significantly....
Stochastic dynamics of electronic wave packets in fluctuating laser fields (2000)
The dynamics of a laser-excited Rydberg electron under the influence of a fluctuating laser field are investigated. Rate equations are developed which describe these dynamics in the limit of large...
Entanglement and the linearity of quantum mechanics (1999)
Optimal universal entanglement processes are discussed which entangle two quantum systems in an optimal way for all possible initial states. It is demonstrated that the linear character of quantum...
A multi-dimensional semiclassical description of excitation of a Rydberg electron by half-cycle pulses is developed and applied to the study of energy- and angle-resolved ionization spectra....
Excitation of weakly bound Rydberg electrons by half-cycle pulses (1999)
The interaction of a weakly bound Rydberg electron with an electromagnetic half-cycle pulse (HCP) is described with the help of a multidimensional semiclassical treatment. This approach relates the...
Destruction of quantum coherence and wave packet dynamic (1999)
The main aim of this article is to discuss characteristic physical phenomena which govern the destruction of quantum coherence of material wave packets.
Probing quantum states of Rydberg electrons by half-cycle pulses (1999)
state of the Rydberg electron manifests itself in the angle- and energy-resolved ionization spectra. Furthermore, this way a detailed understanding of the ionization dynamics is obtained which is...
Mice lacking IL-12 develop polarized Th1 cells during viral infection (1998)
Horzinek, M.C., Schijns, V.E., Haagmans, B.L., Wierda, C.M., Kruithof, B., Heijnen, I.A., ...
Studies in IL-12-deficient mice established the necessity for IL-12 to generate a Th1 cytokine response that is often required for elimination of intracellular pathogens. In this study, we...
The Quantum state diffusion model and the driven damped nonlinear oscillator (1996)
Rigo, M., Alber, G., Mota-Furtado, F., O'Mahony, P. F.
We consider a driven damped anharmonic oscillator which classically leads to a bistable steady state and to hysteresis. The quantum counterpart for this system has an exact analytical solution in the...
Interaction of aggregated native and mutant IgE receptors with the cellular skeleton.
Mao, S Y, Alber, G, Rivera, J, Kochan, J, Metzger, H
When aggregated, cell surface proteins become resistant to solubilization by detergents, presumably because of aggregation-induced or -stabilized interactions between the membrane protein and the...
Interleukin-12 is indispensable for protective immunity against Leishmania major.
Mattner, F, Di Padova, K, Alber, G
Interleukin-12 (IL-12)-deficient mice derived from a strain genetically resistant to infection with Leishmania major were recently shown to be susceptible toward this parasite, developing a strong...
Mattner, F, Ozmen, L, Podlaski, F J, Wilkinson, V L, Presky, D H, Gately, M K, ...
The role of interleukin-12 (IL-12) was investigated in different shock models using anti-IL-12 reagents. IL-12 is composed of two disulfide-bonded subunits, p35 and p40. The IL-12 p40 homodimer...
Interaction of aggregated native and mutant IgE receptors with the cellular skeleton.
Mao, S Y, Alber, G, Rivera, J, Kochan, J, Metzger, H
When aggregated, cell surface proteins become resistant to solubilization by detergents, presumably because of aggregation-induced or -stabilized interactions between the membrane protein and the...
Interleukin-12 is indispensable for protective immunity against Leishmania major.
Mattner, F, Di Padova, K, Alber, G
Interleukin-12 (IL-12)-deficient mice derived from a strain genetically resistant to infection with Leishmania major were recently shown to be susceptible toward this parasite, developing a strong...
Mattner, F, Ozmen, L, Podlaski, F J, Wilkinson, V L, Presky, D H, Gately, M K, ...
The role of interleukin-12 (IL-12) was investigated in different shock models using anti-IL-12 reagents. IL-12 is composed of two disulfide-bonded subunits, p35 and p40. The IL-12 p40 homodimer...