Go toArchive
Browse byFacets
Bookbag ( 0 )
Facet   section ZfN Section A:Volume 056  [X]
Results  147 Items
Sorted by   
Publication Year
2001 (147)
1Author    Yakir Aharonova, Alonso Boterob, Marian ScullyaRequires cookie*
 Title    Locality or Non-Locality in Quantum Mechanics: Hidden Variables without "Spooky Action-at-a-Distance"  
 Abstract    The folklore notion o f the "Non-Locality o f Quantum Mechanics" is examined from the point of view o f hidden-variables theories according to Belinfante's classification in his Survey o f Hidden Variables Theories. It is here shown that in the case o f EPR, there exist hidden variables theories that successfully reproduce quantum-mechanical predictions, but which are explicitly local. Since such theories do not fall into Belinfante's classification, we propose an expanded classification which includes similar theories, which we term as theories o f the "third" kind. Causal implications of such theories are explored. -Pacs: 03.65.Bz 
  Reference    Z. Naturforsch. 56a, 5—1235 (2001); received February 16 2001 
  Published    2001 
  Keywords    Non-Locality, Hidden Variables, EPR 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_A/56/ZNA-2001-56a-0005.pdf 
 Identifier    ZNA-2001-56a-0005 
 Volume    56 
2Author    Yakir Aharonova, Berthold-Georg EnglertcRequires cookie*
 Title    The Mean King's Problem: Spin  
 Abstract    We show how one can ascertain the values o f four mutually complementary observables o f a spin-1 degree o f freedom. -Pacs: 03.65.Bz 
  Reference    Z. Naturforsch. 56a, 16—19 (2001); received January 12 2001 
  Published    2001 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_A/56/ZNA-2001-56a-0016.pdf 
 Identifier    ZNA-2001-56a-0016 
 Volume    56 
3Author    Y. Aharonova, L. VaidmanaRequires cookie*
 Title    Sending Signals to Space-Like Separated Regions  
  Reference    Z. Naturforsch. 56a, 20—2 (2001); received February 8 2001 
  Published    2001 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_A/56/ZNA-2001-56a-0020.pdf 
 Identifier    ZNA-2001-56a-0020 
 Volume    56 
4Author    DimitrisG. Angelakis, Almut Beigea, PeterL. Knight, WilliamJ. Munrob, Ben TregennaRequires cookie*
 Title    Verifying Atom Entanglement Schemes by Testing Bell's Inequality  
 Abstract    Recent experiments to test B ell's inequality using entangled photons and ions aimed at tests of basic quantum mechanical principles. Interesting results have been obtained and many loopholes could be closed. In this paper we want to point out that tests of Bell's inequality also play an important role in verifying atom entanglement schemes. We describe as an example a scheme to prepare arbitrary entangled states o f N two-level atoms using a leaky optical cavity and a scheme to entangle atoms inside a photonic crystal. During the state preparation no photons are emitted, and observing a violation o f B ell's inequality is the only way to test whether a scheme works with a high precision or not. 
  Reference    Z. Naturforsch. 56a, 27 (2001); received February 16 2001 
  Published    2001 
  Keywords    Present address: Hewlett-Packard Laboratories, Filton Road, Stoke Gifford, Bristol BS34 8QZ, UK Key words: Bell Inequality Tests, Atom Entanglement Schemes, Quantum Computing, Manipulation o f Decoherence-free States 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_A/56/ZNA-2001-56a-0027.pdf 
 Identifier    ZNA-2001-56a-0027 
 Volume    56 
5Author    NicholasP. BigelowRequires cookie*
 Title    Spin Squeezing in Degenerate and Non-degenerate Atomic Vapors: Some Approaches to Atomic Entanglement  
  Reference    Z. Naturforsch. 56a, 35 (2001); received February 20 2001 
  Published    2001 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_A/56/ZNA-2001-56a-0035.pdf 
 Identifier    ZNA-2001-56a-0035 
 Volume    56 
6Author    R. Bonifacio, S. OlivaresRequires cookie*
 Title    Young's Experiment, Schrödinger's Spread and Spontaneous Intrinsic Decoherence  
  Reference    Z. Naturforsch. 56a, 41—47 (2001); received February 3 2001 
  Published    2001 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_A/56/ZNA-2001-56a-0041.pdf 
 Identifier    ZNA-2001-56a-0041 
 Volume    56 
7Author    M. A. Cirone3, G. Metikas3, W. P. SchleichaRequires cookie*
 Title    Unusual Bound or Localized States  
  Reference    Z. Naturforsch. 56a, 48—6 (2001); received February 11 2001 
  Published    2001 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_A/56/ZNA-2001-56a-0048.pdf 
 Identifier    ZNA-2001-56a-0048 
 Volume    56 
8Author    Francesco De Martini, GiovanniDi GiuseppeRequires cookie*
 Title    Multiparticle Quantum Superposition and Stimulated Entanglement by Parity Selective Amplification of Entangled States  
  Reference    Z. Naturforsch. 56a, 61—66 (2001); received February 3 2001 
  Published    2001 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_A/56/ZNA-2001-56a-0061.pdf 
 Identifier    ZNA-2001-56a-0061 
 Volume    56 
9Author    DanielM. GreenbergerRequires cookie*
 Title    The Inconsistency of the Usual Galilean Transformation in Quantum Mechanics and How To Fix It  
 Abstract    It is shown that the generally accepted statement that one cannot superpose states of different mass in non-relativistic quantum mechanics is inconsistent. It is pointed out that the extra phase induced in a moving system, which was previously thought to be unphysical, is merely the non-relativistic residue of the "twin-paradox" effect. In general, there are phase effects due to proper time differences between moving frames that do not vanish non-relativistically. There are also effects due to the equivalence of mass and energy in this limit. The remedy is to include both proper time and rest energy non-relativis-tically. This means generalizing the meaning of proper time beyond its classical meaning, and introduc­ ing the mass as its conjugate momentum. The result is an uncertainty principle between proper time and mass that is very general, and an integral role for both concepts as operators in non-relativistic physics. 
  Reference    Z. Naturforsch. 56a, 67—75 (2001); received February 8 2001 
  Published    2001 
  Keywords    Galilean Transformation, Symmetry, Superselection Rules, Proper Time, Mass 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_A/56/ZNA-2001-56a-0067.pdf 
 Identifier    ZNA-2001-56a-0067 
 Volume    56 
10Author    Rudolf HaagRequires cookie*
 Title    Quantum Physics and Reality  
 Abstract    Apparent paradoxes in Quantum Physics demand a sharp distinction between a "real part of the world" and the realm of possibilities. In the former we may distinguish individual elements (coarse events) relating to space-time, with causal connections between them respecting the relativistic locality principle. The latter, quantitatively described by probability assignments conditioned on existing facts and depending on the definition of equivalence classes of situations, cannot be subdivided in space-time categories. There are global correlations (Pauli principle...). The cut between the realms of facts and possibilities implies an evolutionary picture of the "real world" in which the (generalized) arrow of time assumes basic significance. Some deficiencies of existing theory are pointed out. 
  Reference    Z. Naturforsch. 56a, 76—82 (2001); received January 12 2001 
  Published    2001 
  Keywords    Quantum Philosophy, Entanglement, Irreversibility 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_A/56/ZNA-2001-56a-0076.pdf 
 Identifier    ZNA-2001-56a-0076 
 Volume    56 
11Author    A. G. Kofman, G. KurizkiRequires cookie*
 Title    Frequent Observations Accelerate Decay: The anti-Zeno Effect  
 Abstract    The quantum Zeno effect (QZE) is the striking prediction that the decay of any unstable quan­ tum state can be inhibited by sufficiently frequent observations (measurements). The consensus 
  Reference    Z. Naturforsch. 56a, 83—90 (2001); received February 6 2001 
  Published    2001 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_A/56/ZNA-2001-56a-0083.pdf 
 Identifier    ZNA-2001-56a-0083 
 Volume    56 
12Author    B. Kraus, W. Dür, G. Vidal, J. I. Cirac, M. Lewensteina, N. Lindenb, S. Popescuc, H. H.Requires cookie*
 Title    Entanglement Capability of Two-qubit Operations  
 Abstract    We study the optimal way of creating bi-partite entanglement using a general two-qubit in­ teraction. On the one hand, we analyze the entanglement capability of an arbitrary non-local Hamiltonian acting on two qubits. We explicitly calculate the state which maximizes the entangle­ ment produced per time step 81 during the non-local evolution. On the other hand, we determine the maximal amount of entanglement which can be produced by an arbitrary two-qubit gate. We also give the separable state which leads to the output state containing this amount of entanglement. Furthermore, we consider the situation where auxiliary systems are present. Finally, we determine the non-unitary processes which are able to create entanglement from an initially separable state of two systems. 
  Reference    Z. Naturforsch. 56a, 91—99 (2001); received February 6 2001 
  Published    2001 
  Keywords    Entanglement, Quantum Information, Quantum Gates 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_A/56/ZNA-2001-56a-0091.pdf 
 Identifier    ZNA-2001-56a-0091 
 Volume    56 
13Author    L. VaidmanRequires cookie*
 Title    The Paradoxes of the Interaction-free Measurements  
 Abstract    Interaction-free measurements introduced by Elitzur and Vaidman [Found. Phys. 23,987 (1993)] allow finding infinitely fragile objects without destroying them. Paradoxical features of these and related measurements are discussed. The resolution of the paradoxes in the framework of the Many-Worlds Interpretation is proposed. 
  Reference    Z. Naturforsch. 56a, 100—107 (2001); received January 12 2001 
  Published    2001 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_A/56/ZNA-2001-56a-0100.pdf 
 Identifier    ZNA-2001-56a-0100 
 Volume    56 
14Author    David Vitali, Giacomo Ciaramicoli, Paolo TombesiRequires cookie*
 Title    A Cavity QED Source for Entangled Photons  
 Abstract    We study the possible limitations and sources of decoherence of a scheme for the deterministic generation of polarization-entangled photons based on an appropriately driven single atom trapped within an optical cavity. -Pacs: 03.67.Hk, 42.50.Gy, 32.80.Qk 
  Reference    Z. Naturforsch. 56a, 108—116 (2001); received January 12 2001 
  Published    2001 
  Keywords    Entanglement, Quantum Decoherence, Cavity QED 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_A/56/ZNA-2001-56a-0108.pdf 
 Identifier    ZNA-2001-56a-0108 
 Volume    56 
15Author    HerbertW. AltherRequires cookie*
 Title    Generation and Detection of Fock-States of the Radiation Field  
 Abstract    In this paper we give a survey o f our experiments performed with the micromaser on the generation of Fock states. Three methods can be used for this purpose: the trapping states leading to Fock states in a continuous wave operation, state reduction o f a pulsed pumping beam, and finally using a pulsed pumping beam to produce Fock states on demand where trapping states stabilize the photon number. 
  Reference    Z. Naturforsch. 56a, 117—123 (2001); received January 12 2001 
  Published    2001 
  Keywords    Quantum Optics, Cavity Quantum Electrodynamics, Nonclassical States, Fock States, One-Atom-Maser 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_A/56/ZNA-2001-56a-0117.pdf 
 Identifier    ZNA-2001-56a-0117 
 Volume    56 
16Author    Ph Blanchard, R. O. LkiewRequires cookie*
 Title    Decoherence, Classical Properties and Entanglement of Quantum Systems  
  Reference    Z. Naturforsch. 56a, 124—127 (2001); received February 8 2001 
  Published    2001 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_A/56/ZNA-2001-56a-0124.pdf 
 Identifier    ZNA-2001-56a-0124 
 Volume    56 
17Author    E. Delre, B. Crosignani3, R.Di Porto3Requires cookie*
 Title    Bell States, Bell Operators, and Total Teleportation  
 Abstract    We identify the operators and the corresponding physical quantities whose measurement allows in principle to obtain total teleportation o f the unknown spin state of a single electron. We introduce an analogous scheme for a single photon and discuss its experimental implementation. 
  Reference    Z. Naturforsch. 56a, 128—132 (2001); received February 3 2001 
  Published    2001 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_A/56/ZNA-2001-56a-0128.pdf 
 Identifier    ZNA-2001-56a-0128 
 Volume    56 
18Author    P. D. Drumm, S. Chaturvedi, K. Dechoum, J. ComRequires cookie*
 Title    Quantum Criticality  
 Abstract    We investigate the theory of quantum fluctuations in non-equilibrium systems having large crit­ ical fluctuations. This allows us to treat the limits imposed by nonlinearities to quantum squeezing and noise reduction, and also to envisage future tests o f quantum theory in regions of macroscopic quantum fluctuations. A long-term objective of this research is to identify suitable physical sys­ tems in which macroscopic 'Schrödinger cat'-like behaviour may be observed. We investigate two systems in particular o f much current experimental interest, namely the degenerate parametric oscillator near threshold, and the evaporatively cooled (BEC). We compare the results obtained in the positive-P representation, as a fully quantum mechanical calculation, with the truncated Wigner phase space equation, also known as semi-classical theory. We show when these results agree and differ in calculations taken beyond the linearized approximation. In the region where the largest quantum fluctuations and Schrödinger cat-like behaviour might be expected, we find that the quantum predictions correspond very closely to the semi-classical theory. Nature abhors observing a Schrödinger cat. -Pacs: 03.65.Bz 
  Reference    Z. Naturforsch. 56a, 133—139 (2001); received January 12 2001 
  Published    2001 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_A/56/ZNA-2001-56a-0133.pdf 
 Identifier    ZNA-2001-56a-0133 
 Volume    56 
19Author    Folm, J. Schm Iedm Ayerb, H. Ritschc, D. VitaliRequires cookie*
 Title     
  Reference    Z. Naturforsch. 56a, 140—144 (2001); received February 6 2001 
  Published    2001 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_A/56/ZNA-2001-56a-0140.pdf 
 Identifier    ZNA-2001-56a-0140 
 Volume    56 
20Author    M. Auro Fortunato, M. Ichol Massini, Stefano Mancini, Paolo TombesiRequires cookie*
 Title    Entangled State Reconstruction of an Electron in the Penning Trap  
 Abstract    We apply a tomographic method we have recently proposed to the reconstruction of the full entangled quantum state for the cyclotron and spin degrees of freedom o f a trapped electron. Our numerical simulations show that the entangled state is accurately reconstructed. -Pacs: 03.65. 
  Reference    Z. Naturforsch. 56a, 145—151 (2001); received February 15 2001 
  Published    2001 
  Keywords    State Reconstruction, Entanglement, Trapped Electron, Penning Trap, Quantum Information 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_A/56/ZNA-2001-56a-0145.pdf 
 Identifier    ZNA-2001-56a-0145 
 Volume    56 
1
2
3
4
5
...
Next