Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

The Rochester Conferences on Coherence and Quantum Optics and the Quantum Information and Measurement meeting

Entanglement Dynamics in the Presence of Unital Noisy Channels

Assaf Shaham, A. Halevy, Liat Dovrat, E. Megidish, H. S. Eisenberg

Published Jan 1, 2013• 0 citations
Publisher

Abstract

The entanglement level of two initially entangled qubits, subjected to an uncorrelated unital noisy channel is simply manifested by the radii of its Bloch sphere mapping. We demonstrate this relation experimentally using an all-optical setup.
DOI
10.1364/cqo.2013.m6.23

Related papers

Entanglement Dynamics in the Presence of Unital Noisy Channels

Assaf Shaham, A. Halevy, Liat Dovrat +2 more

The entanglement level of two initially entangled qubits, subjected to an uncorrelated unital noisy channel is simply manifested by the radii of its Bloch sphere mapping. We demonstrate this relation experimentally using an all-optical setup.

•Jan 1, 2013•0 citations

Entanglement Dynamics in the Presence of Unital Noise

Assaf Shaham, A. Halevy, Liat Dovrat +2 more

The entanglement level of two entangled qubits that are subjected to an uncorrelated unital noise is simply manifested by the Bloch sphere representation of noise. We verified experimentally this relation using an all-optical setup.

Frontiers in Optics•Jan 1, 2012•0 citations

Entanglement dynamics in the presence of controlled unital noise

A. Shaham, A. Halevy, L. Dovrat +2 more

Quantum entanglement is notorious for being a very fragile resource. Significant efforts have been put into the study of entanglement degradation in the presence of a realistic noisy environment. Here, we present a theoretical and an experimental study of the decoherence properties of entangled pairs of qubits. The entanglement dynamics of maximally entangled qubit pairs is shown to be related in a simple way to the noise representation in the Bloch sphere picture. We derive the entanglement level in the case when both qubits of a Bell state are transmitted through any arbitrary unital Pauli channel, and compare it to the case when the channel is applied only to one of the qubits. The dynamics of both cases was verified experimentally using an all-optical setup. We further investigated the evolution of partially entangled initial states. Different dynamics was observed for initial mixed and pure states of the same entanglement level.

arXiv:1405.7314•Scientific Reports•Jun 10, 2015•11 citations

Bloch-sphere approach to correlated noise in coupled qubits

Håkon Brox, Joakim Bergli, Y. M. Galperin

In order to demonstrate a generalized Bloch-sphere approach for the treatment of noise in coupled qubits, we perform a case study of the decoherence of a system composed of two interacting qubits in a noisy environment. In particular, we investigate the effects of correlations in the noise acting on distinct qubits. Our treatment of the two-qubit system by use of the generalized Bloch vector leads to tractable analytic equations for the dynamics of the four-level Bloch vector and allows for the application of geometrical concepts from the well-known two-level Bloch sphere. We find that in the presence of correlated or anticorrelated noise, the rate of decoherence is very sensitive to the initial two-qubit state, as well as to the symmetry of the Hamiltonian. In the absence of symmetry in the Hamiltonian, correlations only weakly impact the decoherence rate.

arXiv:1205.0457•Journal of Physics A Mathematical and Theoretical•Oct 18, 2012•8 citations

Determining the Dynamics of Entanglement

O. Jiménez Farías, Camille Lombard Latune, Stephen Patrick Walborn +2 more

The estimation of the entanglement of multipartite systems undergoing decoherence is important for assessing the robustness of quantum information processes. It usually requires access to the final state and its full reconstruction through quantum tomography. General dynamical laws may simplify this task. We found that when one of the parties of an initially entangled two-qubit system is subject to a noisy channel, a single universal curve describes the dynamics of entanglement for both pure and mixed states, including those for which entanglement suddenly disappears. Our result, which is experimentally demonstrated using a linear optics setup, leads to a direct and efficient determination of entanglement through the knowledge of the initial state and single-party process tomography alone, foregoing the need to reconstruct the final state.

Science•May 15, 2009•73 citations

Experimental Characterization of Entanglement Dynamics in Noisy Channels

Jin‐Shi Xu, Chuan‐Feng Li, Xiao‐Ye Xu +3 more

We experimentally characterize the bipartite entanglement under one-sided open system dynamics and verify the recently formulated entanglement factorization law [Nature Phys. 4, 99 (2008)]. The one-sided open system dynamics is realized by implementing a phase damping and an amplitude decay channel, respectively, acting on one of the qubits, by an all-optical setup. Our results greatly simplify the characterization of entanglement dynamics and will play an important role in the construction of complex quantum networks.

arXiv:0905.3442•Physical Review Letters•Dec 9, 2009•39 citations
Quantum entanglement is notorious for being a very fragile resource. Significant efforts have been put into the study of entanglement degradation in the presence of a realistic noisy environment. Here, we present a theoretical and an experimental study of the decoherence properties of entangled pairs of qubits. The entanglement dynamics of maximally entangled qubit pairs is shown to be related in a simple way to the noise representation in the Bloch sphere picture. We derive the entanglement level in the case when both qubits of a Bell state are transmitted through any arbitrary unital Pauli channel, and compare it to the case when the channel is applied only to one of the qubits. The dynamics of both cases was verified experimentally using an all-optical setup. We further investigated the evolution of partially entangled initial states. Different dynamics was observed for initial mixed and pure states of the same entanglement level.
In order to demonstrate a generalized Bloch-sphere approach for the treatment of noise in coupled qubits, we perform a case study of the decoherence of a system composed of two interacting qubits in a noisy environment. In particular, we investigate the effects of correlations in the noise acting on distinct qubits. Our treatment of the two-qubit system by use of the generalized Bloch vector leads to tractable analytic equations for the dynamics of the four-level Bloch vector and allows for the application of geometrical concepts from the well-known two-level Bloch sphere. We find that in the presence of correlated or anticorrelated noise, the rate of decoherence is very sensitive to the initial two-qubit state, as well as to the symmetry of the Hamiltonian. In the absence of symmetry in the Hamiltonian, correlations only weakly impact the decoherence rate.
The estimation of the entanglement of multipartite systems undergoing decoherence is important for assessing the robustness of quantum information processes. It usually requires access to the final state and its full reconstruction through quantum tomography. General dynamical laws may simplify this task. We found that when one of the parties of an initially entangled two-qubit system is subject to a noisy channel, a single universal curve describes the dynamics of entanglement for both pure and mixed states, including those for which entanglement suddenly disappears. Our result, which is experimentally demonstrated using a linear optics setup, leads to a direct and efficient determination of entanglement through the knowledge of the initial state and single-party process tomography alone, foregoing the need to reconstruct the final state.
We experimentally characterize the bipartite entanglement under one-sided open system dynamics and verify the recently formulated entanglement factorization law [Nature Phys. 4, 99 (2008)]. The one-sided open system dynamics is realized by implementing a phase damping and an amplitude decay channel, respectively, acting on one of the qubits, by an all-optical setup. Our results greatly simplify the characterization of entanglement dynamics and will play an important role in the construction of complex quantum networks.