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Related papers: Polarization and entanglement in spin systems

200 papers

We show how entanglement may be quantified in spin and cold atom many-body systems using standard experimental techniques only. The scheme requires no assumptions on the state in the laboratory and a lower bound to the entanglement can be…

Quantum Physics · Physics 2013-05-29 M. Cramer , M. B. Plenio , H. Wunderlich

We investigate numerically the time dependence of the multiple quantum coherences and entanglement in linear chains up to nine nuclear spins of 1/2 coupled by the dipole-dipole interactions. Two models are considered: (1) a spin chain with…

Quantum Physics · Physics 2009-11-13 G. B. Furman , V. M. Meerovich , V. L. Sokolovsky

Entangled states of two coupled polar molecules controlled by laser pulses are studied theoretically. Schmidt decomposition is used to measure the degree of entanglement. By varying the pulse shape of the applied laser, transition from…

Atomic and Molecular Clusters · Physics 2007-05-23 Y. Y. Liao , Y. N. Chen , D. S. Chuu

Dynamic nuclear polarization (DNP) is a promising strategy for generating a significantly increased non-thermal spin polarization in nuclear magnetic resonance (NMR) applications thereby circumventing the need for strong magnetic fields.…

Quantum Physics · Physics 2015-07-15 Alexander Karabanov , Daniel Wisniewski , Igor Lesanovsky , Walter Köckenberger

Entanglement can improve the measurement precision of quantum sensors beyond the shot noise limit. Neutral atoms, the basis of some of the most precise and accurate optical clocks and interferometers, do not naturally exhibit all-to-all…

We employ a nuclear magnetic resonance (NMR) quantum information processor to simulate the ground state of an XXZ spin chain and measure its NMR analog of entanglement, or pseudo-entanglement. The observed pseudo-entanglement for a…

Quantum Physics · Physics 2011-07-26 Jingfu Zhang , Tzu-Chieh Wei , Raymond Laflamme

Pulsed Dynamic Nuclear Polarization (DNP) is currently receiving substantial interest as a means to enhance the sensitivity of nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) by orders of magnitude. It has also…

We quantify the geometric measure of entanglement in terms of mean values of observables of entangled system. For pure states we find the relation of geometric measure of entanglement with the mean value of spin one-half for the system…

Quantum Physics · Physics 2017-10-11 A. M. Frydryszak , M. I. Samar , V. M. Tkachuk

We study manipulation of entanglement between two identical networks of quantum mechanical particles. Firstly, we reduce the problem of entanglement transfer to the problem of quantum state transfer. Then, we consider entanglement…

Quantum Physics · Physics 2011-01-27 Andrea Casaccino , Stefano Mancini , Simone Severini

We propose a scheme for the deterministic generation of steady-state entanglement between the two nuclear spin ensembles in an electrically defined double quantum dot. Due to quantum interference in the collective coupling to the electronic…

Mesoscale and Nanoscale Physics · Physics 2013-12-23 Martin J. A. Schuetz , Eric M. Kessler , Lieven M. K. Vandersypen , J. Ignacio Cirac , Geza Giedke

Entanglement generated by Ising model has been studied for several authors in order to understand the relation between it and magnetic properties of materials, principally using one or two dimensional models for two or more particles. In…

Quantum Physics · Physics 2008-10-01 Francisco Delgado

A quantum-mechanical many-particle system may exhibit non-local behavior in that measurements performed on one of the particles can affect a second one that is far apart. These so-called entangled states are crucial for the implementation…

Other Condensed Matter · Physics 2009-11-10 J. M. Bao , A. V. Bragas , J. K. Furdyna , R. Merlin

Quantum metrology experiments in atomic physics and quantum optics have demonstrated measurement accuracy beyond the shot-noise limit via multi-particle entanglement. At the same time, electron microscopy, an essential tool for…

Given an ensemble of n spins, at least some of which are partially polarized, we investigate the sharing of this polarization within a subspace of k spins. We assume that the sharing results in a pseudopure state, characterized by a single…

Quantum Physics · Physics 2007-05-23 M. S. Anwar , J. A. Jones , S. B. Duckett

We produce polarization entangled states with variable degree of entanglement for twin photons. Entanglement in polarization is coupled to entanglement in position that produces transverse coincidence interference fringes. We show both…

Quantum Physics · Physics 2009-11-07 M. Franca Santos , P. Milman , A. Z. Khoury , P. H. Souto Ribeiro

The spin-dynamics of two alkali atoms in an optical tweezer is driven by spin-changing collisions that couple the spin-state of the atoms to their relative motion. This paper experimentally studies the resulting spin-states when the…

Quantum control and measurement are two sides of the same coin. To affect a dynamical map, well-designed time-dependent control fields must be applied to the system of interest. To read out the quantum state, information about the system…

Quantum Physics · Physics 2015-05-14 Ivan H. Deutsch , Poul S. Jessen

A general description of entanglement is suggested as an action realized by an arbitrary operator over given disentangled states. The related entanglement measure is defined. Because of its generality, this definition can be employed for…

Quantum Physics · Physics 2009-11-10 V. I. Yukalov

We study entanglement between quantum states of multi level spin system of a single particle considering a nucleus with spin 3/2 in both the internal electric field gradient and the external magnetic field. It was shown that entanglement is…

Quantum Physics · Physics 2010-06-21 G. B. Furman , V. M. Meerovich , V. L. Sokolovsky

We consider pure quantum states of $N\gg 1$ spins or qubits and study the average entanglement that can be \emph{localized} between two separated spins by performing local measurements on the other individual spins. We show that all…

Quantum Physics · Physics 2007-05-23 F. Verstraete , M. Popp , J. I. Cirac