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Related papers: Entanglement of solid-state qubits by measurement

200 papers

We report observations of entanglement of two remote atomic qubits, achieved by generating an entangled state of an atomic qubit and a single photon at Site A, transmitting the photon to Site B in an adjacent laboratory through an optical…

Quantum Physics · Physics 2009-11-11 D. N. Matsukevich , T. Chaneliere , S. D. Jenkins , S. -Y. Lan , T. A. B. Kennedy , A. Kuzmich

We report on the preparation and detection of entangled states between an electron spin 1/2 and a nuclear spin 1/2 in a molecular single crystal. These were created by applying pulses at ESR (9.5 GHz) and NMR (28 MHz) frequencies.…

Quantum Physics · Physics 2009-11-07 M. Mehring , J. Mende , W. Scherer

A 6-qubit hyperentangled state has been realized by entangling two photons in three degrees of freedom. These correspond to the polarization, the longitudinal momentum and the indistinguishable emission produced by a 2-crystal system…

Quantum Physics · Physics 2009-09-29 G. Vallone , R. Ceccarelli , F. De Martini , P. Mataloni

We develop an approach of quantifying entanglement in mixed quantum states by the optimal entanglement witness operator. We identify the convex set of mixed states for which a single witness provides the exact value of an entanglement…

Quantum Physics · Physics 2012-03-07 S. -S. B. Lee , H. -S. Sim

We study the case of two polaritonic qubits localized in two separate cavities coupled by a fiber/additional cavity. We show that surprisingly enough, even a coherent classical pump in the intermediate cavity/fiber can lead to the creation…

Quantum Physics · Physics 2015-05-13 Dimitris G. Angelakis , Stefano Mancini , Sougato Bose

The entanglement of graph states up to eight qubits is calculated in the regime of iteration calculation. The entanglement measures could be the relative entropy of entanglement, the logarithmic robustness or the geometric measure. All 146…

Quantum Physics · Physics 2015-05-14 Xiao-yu Chen

We propose to produce entanglement by measuring the transmission of an optical cavity. Conditioned on the detection of a reflected photon, pairs of atoms in the cavity are prepared in maximally entangled states. The success probability…

Quantum Physics · Physics 2009-11-07 Anders S. Sorensen , Klaus Molmer

We consider qubit networks where adjacent qubits besides interacting via XY-coupling, also dissipate into the same environment. The steady states are computed exactly for all network sizes and topologies, showing that they are always…

Quantum Physics · Physics 2012-07-27 Morteza Rafiee , Cosmo Lupo , Hossein Mokhtari , Stefano Mancini

We produce and holographically measure entangled qudits encoded in transverse spatial modes of single photons. With the novel use of a quantum state tomography method that only requires two-state superpositions, we achieve the most complete…

We find the nearest product states for arbitrary generalized W states of n qubits, and show that the nearest product state is essentially unique if the W state is highly entangled. It is specified by a unit vector in Euclidean n-dimensional…

Quantum Physics · Physics 2010-05-19 Sayatnova Tamaryan , Anthony Sudbery , Levon Tamaryan

We propose a measure of entanglement that can be computed for any pure state of an $M$-qubit system. The entanglement measure has the form of a distance that we derive from an adapted application of the Fubini-Study metric. This measure is…

We propose that the entanglement of mixed states is characterised properly in terms of a probability density function $\mathcal{P}_{\rho}(\mathcal{E})$. There is a need for such a measure since the prevalent measures (such as…

Quantum Physics · Physics 2009-11-13 Shanthanu Bhardwaj , V. Ravishankar

We study the conditions when mixtures of entangled pure states with maximally mixed one-qudit reduced density matrices remain entangled. We found that the resulting mixed state remains entangled when the number of entangled pure states to…

Quantum Physics · Physics 2016-06-10 Marvin M. Flores , Eric A. Galapon

The entanglement evolution of two qubits under local, single- and two- sided noisy channels is investigated. It is found that for all pure initial states, the entanglement under a one-sided noisy channel is completely determined by the…

Quantum Physics · Physics 2015-05-20 Jun-Gang Li , Jian Zou , Bin Shao

We present a significantly improved scheme of entanglement detection inspired by local uncertainty relations for a system consisting of two qubits. Developing the underlying idea of local uncertainty relations, namely correlations, we…

Quantum Physics · Physics 2016-08-16 Christian Kothe , Gunnar Björk

We show a mechanism that projects a pair of neutral two-level atoms from an initially uncorrelated state to a maximally entangled state while they remain spacelike separated. The atoms begin both excited in a common electromagnetic vacuum,…

Quantum Physics · Physics 2009-11-13 Juan León , Carlos Sabín

We examine the stochastic dynamics of entanglement for an uncoupled two-qubit system, undergoing continuous parity measurement. Starting with a fully mixed state, the entanglement is zero for a finite amount of time, when it is suddenly…

Quantum Physics · Physics 2008-12-12 Nathan S. Williams , Andrew N. Jordan

We introduce a feasible method of constructing the entanglement witness that detects the genuine entanglement of a given pure multiqubit state. We illustrate our method in the scenario of constructing the witnesses for the multiqubit states…

Quantum Physics · Physics 2009-11-13 Lin Chen , Yi-Xin Chen

When a superposition $(|\alpha>-|-\alpha>)$ of two coherent states with opposite phase falls upon a 50-50 beamsplitter, the resulting state is entangled. Remarkably, the amount of entanglement is exactly 1 ebit, irrespective of $\alpha$, as…

Quantum Physics · Physics 2009-11-06 S. J. van Enk , O. Hirota

The state of an entangled q-bit pair is specified by 15 numerical parameters that are naturally regarded as the components of two 3-vectors and a $3\times3$-dyadic. There are easy-to-use criteria to check whether a given pair of 3-vectors…

Quantum Physics · Physics 2015-06-26 Berthold-Georg Englert , Nasser Metwally